Glad to be of service

That depends on what you consider "success". It would certainly remain a niche product. Not that it is exactly mainstream now. It would limit the clientelle to those who are serious about an alternative, rather than just "bi-curious". Which I consider a good thing. The puzzled looks on absolutely everyone's face when I tried to sell them the idea of Sailfish with the main selling point that "don't worry, you can still run Android apps on it" was enough of an argument for me. Literally everyone just (righfully, IMO) asked, "why should I not just get an Android phone, then?".

There are also significant costs associated with Android support. Money spent on AD licencing could be saved or spent on something else. More importantly, the time and effort spent on supporting it could be used more productively on something else. For example, developing native apps (either in-house or by better supporting 3rd party devs) when there is no incentive now, because "Android is the answer to everything."

Lifeboat? Maybe. But lifeboats are not meant to be used! They are the last resort, not the first. If you design your ship in such a way that lifeboats are an integral part of its day-to-day operation right from the start, then you are doing something seriously wrong.