If you closely follow what happened to MJ all along, things fall into place and the picture of Michaels last years seem clearer.
It is said that John Branca quit working for Michael because of Michaels association with 'other' influences in his life. Remember that Branca is a lawyer and he worked on deals for Michael and he knew right from wrong and would have to deal with whatever Michael signed. I could easily understand why someone would fling their hands up in despair and back away from someone who lets these kinds of people into their life and signs contracts such as Michael did.
I can also see Michaels side of things. He was used to living the good life and he was no longer bringing in the same amount of money and needed to work on cash flow. It appears that he backed himself more and more into the corner and Tohme Tohme was not thinking of Michaels best interests here. He may be a financial wizard, but its funny how a lot of Michaels money went so quickly. Add to the mix that his own family is somehow involved here and it makes me angry and ill at the same time.
I think Michael was so upset and distraught about the accusations and the trials and the fallout and he just so desperately needed DOWN TIME and this man came along when he was most vulnerable to 'help him' deal with his financial situation and get him back on track. His family knew his weakness too and I think some of them were very resentful that MJ made it so big while they didn't.
Clearly, Michael went through a horrible emotional time and he wanted to be a good father and not have to deal with any more stress. So...when someone comes along who is going to 'save you' from that stress it looks appealing. I think he was not always capable of making sound decisions because he was so stressed out at the time and people took advantage of that.