Which is what? Lines of code? I think that's even worse.
How do you determine how much work to assign someone if estimates are meaningless? How do you determine if someone is productive or is doing one hour's work per week?
Aside from insults, I don't really see any answers. Have you ever been in a PM role?
Again, if you adjust estimates as you're doing the work ... as in, it's more complex than you thought, so you adjust the estimate ... why are estimates a bad metric and what metric (something that can be quantified) would you recommend?