In every format, there are people who end up purchasing too much camera for their skill level and needs. At some point of time, they WILL downgrade and feel an incessant need to justify the downgrade. The thing is that MF is a significant investment, so MF downgraders tend to be louder than the rest. Apply some internet amplification and well... You know how it goes.
What HAS happened though is that the MF market has seen significant consolidation and reduction in the number of players. This is no different than what happened with 135 format when digital became a thing. Everyone and their grandma started making DSLRs, but in the end, only two figured out how to make money from it. The rest got marginalized, folded or got assimilated into larger corporations. And that was the status quo until some of the formerly marginalized players figured out that the mirror can be taken out. Then began the next gold rush with everyone and their grandma making mirror less systems. A few years down the line, only one of them had figured out how to make money off it. The rest have again become marginalized, assimilated or have unverified rumors about leaving the market (cough Samsung, cough).
Sounds familiar? It should, because that is exactly what is happening with MF. This is the natural order of progression. I hope at least 2 are left standing in the end though, because competition breeds innovation.
The scavengers can set the knives aside. This baby ain't dead.