Here's irony for you. Before poly, my husband was not meeting my needs. Now, thanks to the blessing of the need for better communication, we're doing better than we have previously in our entire marriage.
I didn't really mean to become poly, but my motivation was not to prevent myself from needing my husband too much. I love my other partners. They add to my life. But if I wanted/needed to become monogamous again, I would not regret allowing my husband to be my only relationship. I would be just as devastated to lose him now as I would have been when we were monogamous.
I will add an observation--even though I haven't had time recently to post much, I've done a lot of watching. I've observed a lot of conscientious, ethical poly-folk online, and only a few that display the tendency that you've observed to try to avoid real emotional entanglement.