Oh, this is just the usual Microsoft Stockholm syndrome. I've been witnessing this for over 20 years now and have been told that it has been a thing for much longer than that.

"No, we can't switch to OpenOffice you weird Open Source hippie! I can't e-mail documents to other people anymore, nobody can open them. Besides, the UI is all different, I won't be able to find anything!"

Then Office 2007 happened, tossing out the waffle menu for the ribbon and people started receiving e-mails with strange docx/xlsx files that nobody could open. IIRC that was still an issue 3 years later.

But no, when Microsoft does it, it is different: "This is progress! Are you against progress, you weird Luddite?"

I remember by the time Windows 8 was released ("Kachelofen edition" - "hurr, your desktop is a tablet!"), I was discussing with a Unix graybeard friend in the cafeteria how long it will take until the complainers accept that "this is the way now". I think it was him who suggested that if Microsoft sent a sales rep around to shit on peoples lawns, it would take at most a year until they start defending it as the inevitable cost of technological progress.

No matter how slow and bloated the GitHub web UI gets, or how many nonsense anti-features Microsoft stuffs into it. People will accept it and find funny excuses (network effect will be the main one).