>I honestly believe most MTurkers just clicked random BS in order to complete the tasks as soon as possible.
This is correct based on my (limited) mechanical turk experience. Most tasks pay peanuts (minimum payout can be as low as $0.01) so the only reasonable way to make an income is to complete as many tasks as humanly possible, and doing anything but clicking random buttons would slow them down. I doubt paying more could overcome that because so many people engage with the platform in bad faith.
You can filter out bad workers by preparing an additional well-labeled dataset and removing those who made even a single mistake in it. Also you can give the same task to several workers and check if they give the same label. However this won't protect against a bot using multiple accounts and giving answers based on a hash of a question so that the same question gets the same answer in every account.
This is correct based on my (limited) mechanical turk experience. Most tasks pay peanuts (minimum payout can be as low as $0.01) so the only reasonable way to make an income is to complete as many tasks as humanly possible, and doing anything but clicking random buttons would slow them down. I doubt paying more could overcome that because so many people engage with the platform in bad faith.