On the above-linked article... It said "The thing that I find a little upsetting, however, is when I see "secondary" relationships treated as dispensable. And worse, the person who is the secondary relationship being overlooked as a human being!"
The moment a person is being "overlooked as a human being" one can be sure that there is not love going on, and therefore not polyamory. Real love is fundamentally intimate friendship, where mutual care is what it is all about. Sex and eros can be a part of that, and it can still be love, but the moment the intimate friendship fails the whole thing is no longer love of loving.