Admit it. If Google bought them instead, there'd be far less freakout. Google is pretty scary, but you have to admit that we still distrust MS with our free software even less.
On our self-hosted instance it flies.
Using all of gitlab.com, our self-hosted instance, and github.com with some kind of regularity, I find both GH.com and GL.com equally fast (or "slow" depending on your PoV) since a year or so, and our local instance faster. Neither is rocket fast, but neither is "terribly slow" either, and at any rate they're largely in the same ballpark.
All I want is a Github alternative: something which allows people to clone (be it http(s) or git smart something), do pull requests, have an issue tracker, view files online and show pretty markdown documents. I'm half inclined to go the usual route and write it myself, but I should first google around. Someone mentioned Gitea to me: that project claims to be lightweight so it might already fit the bill.
I think the "if you pay for it" is the differentiator. And because Google supplies far more free services than Microsoft, they get a lot more complaints about non-existent support.
Also your comment that Google abandons things without warning is so wide of the mark as to be plain wrong. We've used Appengine for over ten years, and while they do deprecate features, they give you three years warning (and usually a simple migration path to a superior service). They gave over a year's notice that they were shutting down Google Reader.
I would agree with your last point about trusting your code to Google... or anyone else for that matter. As the mass migration from GitHub to GitLab shows, it is easy to keep your code in multiple repositories. To rely on any single provider (even if that provider is yourself) is irresponsible.
They seem to very deliberately have marketed to middle and upper management for decades. These are levels the majority of companies barely have! Most companies are small, the kind of companies GitHub is 'built' for.
I mean, some people dislike Windows for various reasons, but this falls more into their development umbrella so I trust it is in good hands as ASP.NET, Xamarin, etc. have been in recent years.
The freedom of free software one runs on their own computer means it doesn't matter who holds the copyright to the software. If the copyright holder does something you don't like you have a copy you are free to run, inspect, modify, and share.
Remotely hosted services are a different consideration than free software (see https://www.gnu.org/philosophy/network-services-arent-free-o... for more). With remotely hosted services the user doesn't typically have a copy of the service software. So free software concerns are for the service provider. We hope the service provider runs only free software for their own sake, they deserve to control their own computers just as we deserve to control our computers.
In the particular case of free software and discussions you will publish publicly, you should consider https://www.gnu.org/software/repo-criteria-evaluation.html -- the GNU Project's ethical repo criteria. This was written well before Microsoft was known to have any interest in buying GitHub, possibly during the time when Microsoft was chastising "open source" software for existing (and still despising strongly-copylefted free software) and before their current "Microsoft [heart] open source" publicity campaign. Thus there's no chance GitHub's failing evaluation is based any ad hominem such as whether Google is somehow scarier than Microsoft.