It’s 17m for a tool which hopes to serve companies and charge money and make more than 17m in profit as a result.
If you look at the set of dev tooling, teams will frequently pay many hundreds per dev on things like CI, Git tools, code review, etc.
And to be fair, GitHub is really quite bad for a lot of workflows. I haven’t used gitbutler, but my team pays ~$30 a month per dev for tools which literally just provide a nicer interface for stacking PRs, because it saves us WAY more than that in time.
This isn’t even an egregious example of VC, it’s just an enterprise dev tooling bet.