I am also baffled why people praise FFP.It has destroyed football as far as i'm concerned
Not only it has contributed to the overvaluation of transfer fees but also to the overvaluation of sponsorship deals-see Adidas deal with United.It would've never been so overvalued if not for FFP neither would their tv deals either.
Same 5-6 teams are going to dominate every year.The competitivity is lost.No fun watching the same teams win over and over again imo.
That's not really the fault of FFP though, the development towards that has started long before it was implented, it's simply a result of the commercialisation of football.
I do agree that FFP completely fails at what it tries to do. The only upside is that it hinders Sheik-clubs like City & PSG a bit, but it also makes it much more difficult for rising clubs to establish themselves (see Roma for example). These often simply need to run debts for a few years, if they're successful during that period they'll perhaps cement their place, if not, they'll go bankrupt.
So I see where you're coming from, FFP does facilitate the dominance of a few clubs, but it's not the sole, or even most important reason for it.