Karate [...] and anyone who thinks it is some chump art has not trained at a decent school or just has never trained in it at all.[...]
That's actually the problem. There are not many "decent" schools out there. Most schools train leisure/good feeling Karate (same applies to most other martial arts), because that's what the majority of the average people want when they do martial arts. And I think that's OK. The most dangerous threats the average guy will meet in his life in these days are heart attacks and other health problems caused by lacking mobility - so a bit of leisure martial arts is a good way to diminish those dangers. Unfortunately, that makes it also difficult for those who do want to learn "real" fighting to find a decent school. And that's also the reason for the "bad" reputation of traditional martial arts among competitive oriented fighters.
As for Karate vs. Kickboxing, I'd say according to my experience that in a decent school you get better kicking in Karate, but usually better boxing in Kickboxing, because in most Karate tournaments the head is not a legal target zone for punches (strangely for kicks it is), hence neither punching to the head nor how to avoid/defend punches to the head are trained as good as in Kickboxing where punching to the head is allowed.