It all depends on which organization the tournament falls under. It's best to be familiar with the rules, and stick with an organization that best fits your preferences.
For example, at a USA Karate (formerly USANKF)-sanctioned tournament, disrespect for the referees and judges can result in being tossed out of the tournament, and even banned from that event (unless reinstated). Most of your officiating crew will be certified judges / referees who know the rules, and can apply them properly. While it's not a perfect system (judges are human, after all), it does cut out a lot of the inconsistencies that you'll see with some of the more chaotic tournaments.
If anything, I would encourage you check out one of the USA Karate regional tournaments, if you're interested in clean competition that uses practical rules (sweeps and throws are allowed, strikes to the back are allowed, etc). Just go there as a spectator. Let your experience tell you if it's right for you.
USA Karate
Even though these venues are Karate tournaments, there are some Tae Kwon Do folks who compete at them, and they are certainly welcome to do so, as long as they follow the rules.
Regarding your experience with "open" tournaments, I also share the same sentiment for many of them. The types of sparring that go on sometimes enter the territory of silliness, where these "officials" will give points for someone jumping in the air, and throwing a feeble backfist to someone's body. Or, they'll penalize you for hitting the opponent in the back (even though some of those competitors deliberately turn their backs to you as much as possible in order to exploit a silly rule). Or, a competitor may simply stick his leg in the air, repeatedly kicking at you, knowing that he can't be legally swept or thrown...