I do believe the society as a whole benefits from sugar daddies, as fresh capital are brought into the monetary system of football.
Let's take for example Andy Caroll (although not bought by sugar daddy owned club) . The inflated overpriced Caroll practically funded half of Newcastle squad, making them able to leap frog what supposedly a 5 years progress (if there's no big payout for them, and relying on gate receipt and normal income alone)
The money brought in by Roman and the Sheikh will trickle down to smaller clubs. The easiest example is that by having a sugar daddy funded Chelsea and city, the overall prestige of the EPL will raise, resulting in bigger TV deals which will be divided among EPL clubs.
Not to mention CL will be more exciting with more teams capable of beating one another. Now we have Chelsea, City (although they're out) and PSG as exciting new prospect which are capable of winning the CL. We have the likes of Zenit in Europa League, and Anzhi as well.
The championship will also felt the influx, although not as direct. Smaller clubs getting more from the TV deal will shop more from below them, in a hypothetical market condition.
The point is, massive amount of capital are being brought to the EPL, which is good.
Although it is bad if you're Manchester United.
And let's face it, we're living in the world of free trade and steps are taken to diminishes discrimination in tarrifs all over the world, hence there's no clear cut ways short of discrimination to stop people from wanting to improve their investment.
EDIT : the effect will be good for other nations as well. City buying aguero for close to 50M will means that 50M are going into the spanish flow of money, and it'll also allow Atletico to spend more, going in circle.
So it's not actually bad, how many of us enjoying the City vs United (from a quality game perspective) compared as to the city of the yesteryear?