Everyone is different. I have no doubt that for some people, variety is "a" reason to be poly. For me, it's not even that.
I do tend to be regimented. Comes from being a software engineer, I guess.
But again, people can disregard any part of the gag they wish.
Is there a point to poly without it? What would be the reason for forming a relationship with someone who is a clone of your current partner?
The point to poly for a lot of us is love. We love the other people. We're not looking for "variety" (well, I'm sure some of us are) we find people we love and have relationships with them. I'm inferring from what you're saying that people would actively go out seeking other people to fill in the gaps in their relationships, and that is simply not the case for me. Maybe I'm blessed, but I spent the first eighteen years of my marriage in a relationship with a man who fulfilled me, and I could easily spend the rest of my life with him as my one and only. When there are gaps in our relationship, we work on them together; I don't seek out people who will fix the problem. Now that I have multiple partners, when there are gaps in those relationships, I work on them with my other partners.
Annoying habits is just one example. Another is dysfunction. If one of your partners was suddenly unable to have sex any more, for physical reasons, the other partners would take up the slack. You would just have to concentrate on the other desirable characteristics of that person. But you would not be sexually frustrated, as you would in a mono relationship.
Been there, done that, not brave enough to wear the t-shirt. The end result was that both boys became sexually dysfunctional because of the pressure. Jackrabbit, I think your model fails to take into account the human factor, emotions. How would you feel, for example, if you developed a sexual dysfunction and your partners went out and got someone else to fulfill their sexual needs? Maybe you're supremely confident and wouldn't see it as your own failing, but many people aren't that secure. All of a sudden, they can't do something so their partners stop coming to them. (In my experience, everyone was frustrated. For myself, I don't believe that I can fix my relationship problems by going out and finding a new partner.)
ETA: I'm still reading. As a fairly monogamous-minded person, I'd like to thank you for at least acknowledging that for some people, monogamy is preferred and not necessarily the evil that I've been told it is by a fair number of poly folk.
I would like to hit on the point that other people have brought up about spending time equally. In practice, I've found that not every partner has the same need for attention. I need a fair amount of attention; I spend part of every day with each of my partners unless something else happens, like illness. My partners, however, spend differing amounts of time and attention with me--one partner sees me about 15 minutes in the morning. My primary partner, of course, tries to spend as much time as he has available. However, he sees our girlfriend once or twice a week for a few hours, and she's fine with that. If needs change, we discuss it. It's up to everyone to state what their needs are.
As for variety, you might change the statement that "the whole point" behind poly is variety, to possibly the whole point for you or the whole point for some. The whole point to poly, for me, is actually that I want to have a relationship with my other partners. I don't need variety. I don't actually want variety. I'm not a big change person. I think I'd be a bit happier with less variety. It's been a nasty shock after thousands of years of marriage (that's an exaggeration) to have to get used to *new* personality quirks.
"The liaisons would not be in your regular rotation, and you would not see this person as often, but of course he/she would understand that and would not feel neglected by the infrequent visits." One would hope they would understand that, but in practice it always depends on the person.
"If you are a guy who does things for his partner on Valentine's Day, her birthday, etc., it would be reasonable to do that for all your partners. Needless to say, unless you are rich, that would require smaller, much less expensive gifts. But the women are not losing out, because they are getting gifts from all the guys on their own lists. It balances out. A bunch of little gifts versus one big one. And there is also the old "it's the thought that counts" cliche." Again, in practice it doesn't necessarily work that way. Of course we buy gifts for our other partners on these days, but *I* am the primary. *I* do the hard stuff that other partners do not. I don't get a heck of a lot of time off. I might actually want a little bit better than completely equal from my primary. But I expect my other partners to treat their primaries that way, too.
I find trying to "balance" the lists a little impractical. There's just no way to fix it so that a romantic relationship can come along at the right time to balance your partner's, or you have to close yourself off while your partner looks for someone, etc. Even if you take romance out of the picture and look for just sex, it's still not always easy to find an acceptable partner. Also, there's no way to count on "extra-family expenses" being counterbalanced by benefits coming from other partners. One model I saw that I thought would work in this situation is that each partner in the primary relationship gets an "allowance" that they are able to spend on other partners. Going over that allowance is achieved through discussion between the two of them.
I just want to point out that comparing regular STD testing to the brothels in Nevada is bound to make some people see poly as immoral if they feel that prostitution is immoral. Also, at one point you say that poly between married couples is just like wife-swapping, and in another you point out that wife-swapping is just sex.
This post is getting quite long, so I'm going to try to stop commenting now.
I'm not trying to pick apart the DPG, I'm just telling you how I think it would work in real life, and I really hope you don't feel picked on.