I've been reading a lot about game design lately, and that's changing my view on mapping somewhat.
Mainly that I don't put visuals so high anymore. Don't get me wrong, it's important, but not automatically important.
See, there's different types of players. Some play purely for the core gameplay. The 'dust' people. Those that up their monitor gamma to get a better view on enemies.
Others prefer visuals more, it's more the complete immersion they like. You can think of more types of players but I think you'll get the idea: it's about the public.
If your public are those that like the gameplay only, then you're not going to spend too much time (or, in this situation, wasting time) on visuals.
If your public likes immersion and realistic, or themed, gameplay experience, you'll spend a lot of time getting the visuals and the logical interaction right.
Of course, visuals and gameplay serve more goals. Visuals help sell a game, or map, better. Visuals enhance the immersion. Bad visuals hurt eyes on the other hand.
Gameplay is what keeps people coming back - or not. On the other hand, some people like to explore more than action scene's or other things. Naturally, these people like to see new things every time, so they're more likely to switch to other maps or games faster. Again, public...
I don't think 'good' and 'bad' are so black and white. It depends on if they suit well with their public. Dust193.683.102 maps and the like are horrible in our eyes, but they appeal to a certain public... so why worry about it? I know I wouldn't want to play those maps, but they're not made for me, so that's no problem.
Say, I created a visual masterpiece, that happens to play well too. But I aimed at a public of puzzle-gamers. Then my nice and smooth action-packed level happens to be bad for them.
About not thinking to play... that's the meaning of the word 'amuse'. A-muse. I like to relax and play something easy once in a while too. Most of the time I prefer games that need a little more thinking (and the best of those games award good thinking, but allow little thinking too). I don't always want to spend hours and hours learning something... that's not what people want. They want to play. So, naturally, if a game or map requires you to learn something, either make it simple, or pack it into the playing itself. Half-Life 2 did this fantastically with the gravity gun and the spores. Other games have long manuals and a lot of boring tutorial maps, that totally take the speed out of it and only delay the fun I want to have, up to the point that I give up because I don't think it's worth the investment anymore...
//rant