Note about the translation on the original. It's a "Let you take it easy ticket," in the sense of those "[insert random chore] ticket," type of gift crap you'd get from children that can't buy things.
My point wasn't about warranting death to the yukkuri, but stating that what you said about Twilight would be a highly acceptable course of action, at least, if you won't just send it to be reclycled or something...
It's not really hypocritical. The paper was already ruined with a crappy message (as Unyu pointed out), so it was just scrap. Wasted already. Equivalent to a written-off, destroyed car, not a pristine shiny new one. Well, maybe a used rusty banger, seeing it's not totally ruined. It's already pretty wrecked, so bashing it up further is of no consequence, and it's not as bad as destroying a new car (for people too angry at anon to think, new car means "clean/new paper"). Also, if he didn't kill the yukkuri, it would have gone on to waste more pieces of paper. This unfortunate piece of mister paper was sacrificed for the greater good.
Anon found a use for the other side of the paper, anyway, so it wasn't wasted. Just not the kind of use it seems people would expect or like. Although, a real treehugger would have snatched the paper out the way, smashed down and recycled the sheet.