Undoubtedly, but the extra length does add some value, and not just from the SEO standpoint. As I mentioned in my earlier post, having the title in the URL makes pasting links easier, since you can see at a glance whether you've actually pasted the link you wanted to. The same information is also useful to people who click those links.
For example, given the choice between this link on one hand and this link on the other, which would you be more likely to click?
Both will take you to the same place. But if you hover over the second link, your status bar will show you the thread title, which will at least give you some information about what you'll find on the other side of the link. The first link contains no such information, so you have to rely on the link text for clues as to what you'll find on the other side of the link. If the link text is not descriptive, you end up clicking blind.
I don't know about you, but I'm generally too busy to bother clicking links blindly in hopes that there'll be some useful information on the other side. When I see a link like the first one, I'll probably just ignore it.
Kobaia when you want to change the title of a thread, the old title will still be visible in the URL. And you can't modify the URL because that would be realy bad for SEO and every external links would be broken.
In esoTalk (and I assume Flarum as well), changing the title of a thread does cause the URL to change, so the old title is not visible in the URL. However, that doesn't break external links, because the thread ID number remains unchanged. As long as the thread ID is in place, the forum can display the thread you're looking for, even if you use a URL with inaccurate title information.
That leaves the issue of SEO, a topic which I frankly find very irritating. It seems to me that people as smart as the folks who work at Google should be able to write an algorithm capable of realizing that everything after the thread ID should be ignored. Seems to me SEO should be about optimizing search engines, not optimizing for search engines.
But then I've always been a bit of a dreamer. I also think money should grow on trees. 😛