I don't think you're wrong overall, and it jives with tripleee's reply, but I don't think wanting end-user software to be less buggy than it currently is is asking for "flawless" software.
You're right, I was being hyperbolic. Bugginess in software is a spectrum, and asking why we're not further along that spectrum toward being bug free, is really what the OP is asking. My answer still applies.