Oh yeah....I feel the same way about that. I find that lots of people who approach it that way are doing so from a selfish point of view- as if people exist to please them. The thing I hear most often when they "discover" that they'r poly is "I knew that not just one person could satisfy me". All of a sudden they start feeling all this entitlement. I really want to say "Sorry..people don't exist just for your satisfaction".
Very often those people are more than willing to expect their partner to share them but have a more difficult time sharing their partner. Another friend of mine calls it "poly for the attention".
The trouble is that when people seek others to fulfill their needs, it usually ends up being a rather bottomless pit of need.
That's not to be confused with recognizing and honoring your needs in a relationship. That's more about knowing yourself and what works in a partnership.