Q: You just make it hard as a substitute for good level design.
As IWBTG gets older, this opinion has fallen out of favor a bit, but I still hear it from time to time. I'm not going to pretend to be a master level designer, but comments like this are ignorent to what 'good level design' actually is. Most people think aesthetically, without thinking about the gameplay elements. Aesthetics are actually a big part of it, but that is only a fraction of the whole story.
I Wanna be the Guy is a game about subversion. It's also a humor driven game. Predicting a players actions perfectly as to maximize surprise and humor/frustration is a way a game can have good level design. The level design is accomplishing it's goal and doing so quite well. The pacing of a game like this is also critical. How much the player is expected to die really influences what the next trap should be and how hard it is to overcome.
Random traps are NOT a real crutch. If used wrong, they are SUICIDE for a game's popularity. It's very hard to have a brutal, mean game while still 'tricking' people to finish it. If a game is popular and brutal it probably has something else going on that makes it work. Instead of lashing against them, look at them closer and try and understand how they work. You might not like them, but you'll probably learn something!