Browsers have scrolled less than 100% since forever, but there are differences. Most noticeably, Firefox scrolls (or used to scroll) more than Chromium, and has problems with content hiding more often.

I've found the best way to avoid downvotes on HN is to pose your assertion as a question (as sincerely as possible) :)

"This isn't even a problem though." -> "Is this really a problem? I thought that... correct me if I'm wrong!"

Your karma will move in the positive direction almost every time.

Downvotes are likely because one's brain learns, "After you hit the space bar, look at the top of the text you were reading, except 15% lower. That's where the next line will be." Sites screw with this assumption and become very hard to read - even if the text is all visible after a scroll.