Heh, good example. Over here, we had a psyker who ignored Psychic Phenomena/Perils of the Warp altogether because it fitted his character. Like, literally, the first time he rolled a double on the psychic test, the GM just shook his head and the game went on like nothing had happened.
Another example from out gaming group is the whole 01-autosuccess/00-autofail rule that we completely ignore. Or Fate Points. We don't use those things either.
You know, with all your house rules and particular special things you've mentioned about your game. What exactly is left from the book that you actually use. Not that you have to use a thing, but at a certain point you're ignoring a majority of the book.
And this is the issue of saying that bad rules can just be ignored. Sure, one or two rules being ignored is fine (if I'm contradicting myself from earlier, then I've changed my mind on it) But you get to a point where the game system basically becomes useless and becomes a philosophical "is a boat made of completely replaced parts the same boat?" situation.
It's fine if someone hates using any encumbrance to just say to ignore it (at least in a game as unbalanced as DH is). It's different when the rule itself is criticized as badly implemented, which the encumbrance system is. "Here's a half-assed implementation that you can just use whenever you want to," is not a good system for encumbrance. It could be much better, and it could actually benefit the game. Not liking the entire concept of a rule is one thing, but not liking how it's actually implemented is another thing entirely.