Because they are pushy and don't listen.

that is precisely it

Maybe what I should be asking is why the fuck are these universally the people in sales?

Because the profession rewards wearing down targets until they buy.

and as always, i can't figure out if it's capitalism i hate more, or capitalists

i might say capitalists, since theyre the ones perpetuating it

and it might be the case for some retail workers, but i think the worst thing is when theyre hustling for commission. its the worst