I do think there are people out there who are legitimately polyamorous, have the best of intentions, and work hard to make their relationships work.

I also think there are many more people who slap the label "poly" on themselves as an excuse to cheat on their spouse, or become a slave collector.

You can't fix your first relationship by adding a second. If there is something seriously lacking in your primary relationship that you just can't live without, then it is time to find a new primary. Adding a slutty little slave on the side isn't going to make you any happier with your wife.