Being that this discussion board is most frequented by those involved in startups, I would posit the meaning behind "UX, not features" to actually be: Focus on

Being that this discussion board is most frequented by those involved in startups, I would posit the meaning behind "UX, not features" to actually be: Focus on maximizing the experience of a small number of features over doing an adequate job on a large number of features. As Paul Buchheit stated, it's better to make a small number of users love you than a large number of users kind of like you. To do this, maximize the preferred, smaller feature set of that excited minority initially, and then expand to encompass the majority only after you've captured that minority.