Probably a host of reasons. MS had 90%+ of the OS marketshare (Excel had ~90% of the spreadsheet market). I think it's hard for people to understand just how do

Probably a host of reasons. MS had 90%+ of the OS marketshare (Excel had ~90% of the spreadsheet market). I think it's hard for people to understand just how dominant MS was at the time - closest might be peak Google with search. Bill G while likable today because of his philanthropy, was really painted then as a ruthless businessman. MS ignored DC and politics for the most part. At the time, the west coast was even more of a different world than what was going on in DC. All the companies today learned from MS. They have armies of lobbyists and court politicians. They are all ruthless business people, but come across as more human and cuddly. They have become key parts of the US economy. I think there's also some fear that if they do go after big tech they could inadvertently make things worse for constituents. Remember, the only thing a politician thinks about is getting re-elected.