The legacy BIOS boot system and MBR format has some real issues that could be improved but this just sounds like an ideological battle against things inspired by Microsoft rather than legitimate technical concerns. As far as I know, despite the things you list having Microsoft roots, they are well-documented and have free/libre implementations so Microsoft influences are not really a problem.

The main problem you have is that convincing manufacturers and proprietary OS makers (including Microsoft) to switch to a hypothetical UEFI replacement free of those issues is going to be an impossible task, while UEFI is already here and while not perfect appears to be better than the legacy BIOS boot system.