Owners like Glazer, who suck money out of football and put clubs in huge debt, are just fine but owners that put money into football (as well as the community) and clear club debts, well, they are evil. It's pretty backwards really. At best, even if you take the naive interpretation of it, FFP is only doing half a job.
Depends where you're looking at it from. Would United fans rather an owner who randomly gave us a billion pounds for absolutely nothing, with no hope of ever recouping it? Why yes, yes we would.
But unlike Sheikh Mansour, at least I understand what the Glazer's are doing. They're horrible, savage uber-capitalists who spotted an opportunity, invested in it, and have made themselves almost a billion dollars from basically risking none of their own money. I understand that.
Is it good for United? No, of course not. But, does it hurt the competitions in which United play? Absolutely not. United did this to themselves by floating on the open market - and they benefited from it historically so can't complain when it comes back to bite them in the ass.
The difference here is that you're viewing it from the fans perspective. UEFA and Premier League on the other hand, are in charge of ensuring 'fair' competition. And having 19 clubs in a league that must make roughly $0 per year of profits to exist and 1 club that can make $100m of losses is not a fair competition. It really is that simple.
The issues this raise is that it will force other clubs - those without limitless pots of petro-dollars - to take on risks that they shouldn't in order to appease their fans and compete. Everyone is pretty happy about LFC's progress this season - but remember they lost over $75m to be where they are. Now, again, they're fortunate in that their owner is willing to pony up this money, but what if they didn't have that?
Why don't Everton lose $75m this coming year, buy all the players they have on loan and bring in one or two more, and then they'd have a comparable squad to LFC? Oh, because THEY CAN'T. The only way to compete with sovereign wealth is more sovereign wealth. Because everyone else has to operate as a business.
Finally, imagine if John Henry has a change of heart now. Or his personal fortunes have issues or whatever. LFC would be forced to sell valuable assets just to be solvent. All plans of a new stadium would be nixed. Ticket prices would have to rise to just to pay wages. That's the problem with having 2 clubs that can live outside their means in the same league as 18 that can't. It puts pressure on the other clubs to act irresponsibly to compete, with a 'Leeds scenario' being a very real risk.
Or far worse, imagine if Sheikh Mansour - who has, I believe, bothered to visit his club about twice in five years - decides on a new hobby. City's squad would be gutted. All the shiny new facilities would not get built. It might even have to declare bankruptcy just to get out of the massive longer term contracts its organic revenue would fail to cover.