I enjoyed this episode of https://roguestartups.com/ where Craig Hewitt discussed what it was like to accept that a product is not getting traction and to let go of it:
The topic in question starts at around 17:35
It is hard to decide when something isn’t working, and when it just needs a bit more time, more polish, or more marketing.
Isn’t lack of traction always just bad marketing? That’s what I was told once.
That is the “even a pig can fly - with enough thrust” approach. It is true that people have made a fortune with clever marketing of stuff that no-one needed. But much better to spend your energies on something that has a ready market IMHO.
Nice quote. 
Have to remember that.
Glad you enjoyed it! I know it was a hard one for Craig…he’s been thinking about it for awhile and it really weighs on you when something isn’t going somewhere and you really, really want it to and put the effort in, but nothing happens.