If you only focus on the most popular features you eventually narrow your product to one feature, so obviously there is a balance in there somewhere between focus and utility as well. Identifying why people use your product is as important as knowing what they use. Chrome does all the things I actually use from Firefox, but I use Firefox because when I ever need slightly more hackability it is there for me. That is at best, a once a year occurance.
If you only focus on the most popular features you eventually narrow your product to one feature, so obviously there is a balance in there somewhere between focus and utility as well. Identifying why people use your product is as important as knowing what they use. Chrome does all the things I actually use from Firefox, but I use Firefox because when I ever need slightly more hackability it is there for me. That is at best, a once a year occurance.