Because they know Forgejo is starting to get attention from major players and thus becoming competitive, and hosting your own CI infrastructure will make completely moving away from GitHub all that easier - If you don't really care about the metadata all it pretty much takes is moving git repositories with their history.
Or shortly summarized: lock in through pricing.
Pretty sure this will explode straight in their faces though. And pretty damn hard.
Or shortly summarized: lock in through pricing.
Pretty sure this will explode straight in their faces though. And pretty damn hard.