Since every single statement in the OP is categorically wrong...
including the one where, I think it is being suggested that the Sigil developers sold out for money -- really? incentive, please

-- who exactly is paying the Sigil developers for the sole purpose of maliciously ruining the program...
I am inclined to think this is spam.
Actually, I am reminded of this thread:
https://www.mobileread.com/forums/sho...d.php?t=263035