Yeah, you make good points. It's business to business like you say and the way I look at it is that good PR here makes the point for good management. Then, for that level of business, buying a football club for 5 to 6 billions make sense? I don't think so. So it must be some sort of PR thing. There are many, many ways to invest that level of money for much better profit.
To summaries, it just does not make sense to me to buy the club from purely a profit point of view given the price and future investment needed. It just doesn't; otherwise the Glazers would not sell to begin with. So it must be much more then cost vs profit/debt over a period of time. There must be other benefits. For the middle east it's sports washing (for Quatar is more then that imo) and for INEOS it must be a PR badge like the F1 Mercedes team. If that is so, then you do not get a publicly loved entity for good will just to cripple it in debt and make all emotionally involved with said entity hate your soul.