Are you implying that there might be some kind of corruption behind? If this is the case, I would not be surprised given the recent cases of money corruption involving some lead politicians of the European Commission. That would be enormous scandal.
I totally agree with you, being granted 100 raises many questions, the most important one is that of equal treatment of all applicants. Many applicants last year have also been granted 100, and I am curious to read those applications and their corresponding evaluation summary reports.
One thing one could do at our level is to unite and ask for a general (well-substantiated) complaint or redress or whatever else, that would increase chances of success. At best, maybe, it would be nice to raise the problem to the awareness of the general scientific and research community. Some would advice to speak to journalists, that would make them panic and act accordingly
. 'But lack of evidence', they would argue. Unless we have someone from the inside… 
Btw, some of us could become experts for the HORIZON CALL, this way one would see how it works from the inside.
Other People here, especially some of those who got it, might argue that the system is fair and that if they got it is due to the absolute absence of any piece of meat in their proposals that the referees might exploit for their critics. This is why you guys have plenty of them over the sections, it is simply not perfectly meat-free.
Choose the side of your story.
Cheers,
A failed MSCA applicant.
