I've written many thousands of words for Soccer Gods on the Glazers and Ferguson's behaviour during the last decade. You can read it, and can do so here, but you can also have a summary of the main arguments.
The damage done to the side by failing to replace the best players to leave:
"There were departures, too, many of which look less reasonable than those of Ronaldo and Bebe. Paul Pogba made just three appearances for Manchester United before joining Juventus for one million pounds per year. Circuitously, he’s been joined in Italy by Carlos Tevez, and both are now key components of the first European Italian force in nearly 10 years. When he moved to Manchester City, Tevez’s astronomical transfer fee went to his owners (not the club), while United had dismantled a front three of Tevez, Rooney and Ronaldo, replacing them with Valencia, Rooney and Dimitar Berbatov. Letting Pogba go was simply gross misconduct on Ferguson’s part."
The dreadful squad that Ferguson left, in need of an overhaul:
"By Ferguson’s latter years, Paul Scholes, Ferdinand, Vidić, Evra, Carrick, Fletcher and others all needed replacing. Every year they remained meant that the squad would require a seismic period of reinvestment, which would then prevent an easy adjustment and would end up costing more. Nani, Young, Valencia, Smalling, Jones and Rafael Da Silva weren’t good enough to carry a new team, again increasing problems for the future."
Ferguson bequeathing a manager out of his depth when a genius was on offer:
"It was obvious when, in the post-match interviews after his Real Madrid team knocked out Manchester United in the Champions League in 2013, Mourinho praised United and Ferguson in lieu of his usual crowing. But for whatever reason, Ferguson anointed Moyes successor. No due diligence, no consensus board decision. He gifted a terrible squad to a manager with no body of evidence to suggest he would do more than struggle."
The sheer scale of the financial cost to Manchester United:
"By that time, some estimates put United’s debt at 773 million pounds, with annual interest payments closing on 70 million pounds. In less than five years, the Glazers had taken a debt-free club and put it in the biggest financial quagmire in England. While estimates of the total debt are not all consistent, the numbers are still scary, even with United posting record revenues each season."
To all those complaining that Ferguson is a genius, or that the Glazers have given him all the money he asked for in the transfer window, then you are invited to enjoy the Champions League semi-finals, including Juventus, Real Madrid, Barcelona and Bayern Munich.
You can read the rest of the blog here.