The MacOS community, and I think many MacOS developers accept that 'sherlocking' is a thing and I see it as something that should be a point of pride for these developers: "we built something so good that Apple decided to rip it off" one oft cited Steve Jobs (through Picaso) quote of course being "good artists copy, great artists steal". But I do understand developers who are frustrated by this happening to their apps, and don't begrudge them for it, especially when it is their source of income.
If Apple were able to copy some app and in return mention your name as a co-author of some sort/tip you - that would probably be a life changing experience for most developers out there.
Losing your income stream certainly is life-changing.
How would Apple admitting they did it change your life for the better?
When you say "tip you", are you thinking "compensate you for all future lost sales and throw in an extra million or two"?
If an acquisition is rejected/infeasible/not applicable/etc, then I'm not clear on the right thing to do. Acquisition might have been possible with Growl, but for some other cases there's not even a company to acquire. Have any other big platforms done this well?
(Apple's acquisition of Workflow which became Shortcuts seems like a case where they did this well)