Surprise!

So I was thinking (I'm always thinking, you know, it's amazing) about Spanish the other day, and particularly about Spanish punctuation. The problem with wanting to think about Spanish punctuation is that I know about three words of Spanish and have absolutely no idea at all when it comes to grammar and structure. Needless to say, this didn't stop me.

What interested me in particular is the way that, in Spanish, questions are bracketed on both sides by punctuation marks. At the beginning there is an upside down question mark, and at the end, a normal one. For example: ¿What's your point, exactly?

My point is coming. Have patience. Okay, so I can see the logic in that. It makes perfectly clear which part of the text is a question, it prepares the reader to be quizzed. But here's what I don't get: they do the same thing with exclamation points. ¡Why, I do exclaim!, he exclaimed.

Yes, the same rationale applies: clarity, preparation. But can't it also ruin the surprise, as far as humor goes? I mean, sometimes the funniest things are the least expected. Doesn't this practice make impossible a very useful grammatical construct, which is to begin a sentence with an appearance of seriousness, and then crack a joke at the end -- a sort of written bait and switch? Isn't that initial inverted exclamation point like a big flashing sign that says Warning! This next part might be humorous!?

Perhaps the very concept of something that's suprisingly funny doesn't exist in Spanish. Or maybe I'm talking out of my ass. Anyone care to elucidate me via a comment?