What you're suggesting is doing two things (paying an interviewee + check, often though to make sure, if he's in it for the sole purpose of interviewee fee) instead of none which has been working just fine for decades.
I'm not necessarily disagreeing with you, but "it's been working just fine for decades" is not a good reason to not change something. In fact, most things would never improve or change at all since most people are terrible at determining what "works just fine" is until they see "works really well".
What you're suggesting is doing two things (paying an interviewee + check, often though to make sure, if he's in it for the sole purpose of interviewee fee) instead of none which has been working just fine for decades.