The graying out of the quote/reply buttons on long posts is implemented in a very unintuitive way where people constantly think they have no way of quoting a post. I believe it's because they are static text that people try to instinctively click it, then see that it doesn't work and then have to just do an @ and say that they can't quote a post.
The hover tooltip solves nothing, as people won't know that it's there, they won't hover their mouse over it for long enough to see something pop up and then read it, and if they're using phones then they sure as hell won't see it because touch interfaces don't have a cursor that can hover over an element.
My suggestion is to make those buttons clickable whilst keeping them white, but making them show a full screen XenForo system message where it then explains how it works.
That way it's way more likely that people will read the note, as it blew up as an error becoming the center of attention, and users will naturally keep the mental note that white button = select text to reply. Right now they don't even get the note that this is the case, they click white text, get mad that it doesn't work and do the same spiel of saying it doesn't work with other users having to tell them what the button should tell them in the first place.
That's my two cents about it.
And just to be clear: THIS IS JUST WHAT I'VE NOTICED ABOUT THE FORUM'S USABILITY THAT I WANTED TO MENTION AND I AM IN NO WAY SHAPE OR FORM TELLING THE OWNER OF THE SITE TO IMPLEMENT THIS CHANGE, I HAVE MERELY EXPRESSED MY OPINION AND HE IS FREE TO COMPLETELY IGNORE IT, AND HE DOES NOT OWE ME AN ANSWER NOR A DIRECT CHANGE TO THE SITE.
