It just made better business sense at the time for him to go with Strikeforce.
Not attacking you specifically but this line of reasoning died 5 years ago.
Vadim and M-1's demands didn't make "business sense" long term. The goal of M-1 was to become a major promotion entity and they failed. This is because their demands were ridiculous, out of whack with the current promotion structure of worldwide MMA (which was UFC and the 7 dwarves in the post-PRIDE era) and no non-UFC entity could survive the financial demands that M-1 was making on them.
M-1 did business with BodogFight which sank BodogFight as a promoter of major events. The organization never recovered financially and could not put on that standard of card ever again after M-1 was done with them.
M-1 did business with Affliction and Affliction hemorrhaged cash in every event that Fedor fought in. Barnett and his needle sank Affliction for good but they could not sustain themselves financially long before that. Fedor's cards needed to sell 3x as well in order for them to even break even.
M-1 did business with Strikeforce which had been successfully promoting and growing their brand over 15 years. 2 years of M-1 crippled the company financially forcing the sell-off to the UFC.
M-1 is no closer to being a global brand and no closer to being a serious promotional entity than they were in 2005 and in fact it's even worse now because at least then they had the #1 fighter in the world as their trump card. Now that Fedor is off the radar they're basically irrelevant.
So if the goal was to do the best thing for M-1 long term, to grow the brand, to grow the sport and to enrich everyone long term, they failed. Miserably.
The only business goal they achieved was for Vadim to shove as much cash in his own personal pocket as possible, leaving rubble in their wake.
I don't see how anyone in 2015 can blame anyone but Vadim for what happened and can't see that Fedor was taken advantage of.