See https://news.ycombinator.com/item?id=23332123 elsewhere in this thread for an example of the consequences.
The cost of GitHub to MS was around 250 usd per user. If 4000 users leave that’s already a million USD.
If more stories like this one come out I'm sure the goodwill turns fast.
When people were warning against Microsoft on this forum they were just set aside as cynical, grumpy Unix-beards. If that happens even here, what do you think will happen elsewhere?
For example, I wanted to buy Win10 recently, and also wanted to sign up for Teams. Both experiences were so unimaginably ridiculously terrible, that I ended up cancelling the Teams subscriptions the same day and not buying Win10.
On the other hand .NET (Core), PowerShell, TypeScript and VS Code are all great things.
Even in their recent history Microsoft has repeated incidents, but also has some very big positive milestones. Also, keeping in mind, some customers will only see the positive milestones.