It is currently maintained by one excellent developer, is featured by the Apple App Store for design... what's the downside?
These firms hirebuy (like acquihire but more money) a single dev with an amazing tool, and not long after the tool is terrible and the dev is out of there.
I think it's fair for the authors of these tools to do well. I encourage creators to monetize when they can. Just get the check up front so you can go create the next thing, because no matter what the acquirer says, you are unlikely to remain aligned.