You either squash them or ignore them.
If you squash them, your capability of developing new features for your users is greatly diminished. If you choose to ignore them, your product will necessarily degrade at increasing pace since you'll develop a culture of negligence (see Broken Windows theory for an explanation). Balancing the two is close to impossible because you cannot have a half-assed culture so one has to choose and the choice is between the future or the present. If you choose squashing bugs, you're forced to make tough choices which might cause you problems today but will eventually help you become successful. If you choose to ignore bugs, you get the illusion of success today while greatly reducing your chances of success tomorrow. While mature companies might opt for today, it makes very little sense for start-ups to do the same.