It's certainly true that the dreaded title fever is a power no mortal can reckon with, only bow before:
https://hn.algolia.com/?sort=byDate&dateRange=all&type=comme...
I guarantee, though, that the solution you mention would make the problem worse. Actually, it's not viable at all, because there's way too much variance in what people put in <title>. It's an HTML jungle out there. But even if you could halfways do it, the titles on the front page would then be so provocative that title fever would be much worse than it is now. And of course there would be a gaping loophole for people to say whatever they wanted on HN's front page just by putting it in <title>. Don't think that wouldn't get abused!
The question is how to minimize all the offtopicness, nitpicking, and bikeshedding that flares up about titles. HN's approach is: (1) use the article's original title unless it is misleading or linkbait; (2) failing that, edit the title to be accurate and neutral, preferably using representative language from the article; (3) if users object, flex until the objections subside; (4) keep the front page 'bookish' (pg's original word).
This is basically an optimization problem (note the word "minimize" above). We learned (3) through trial and error as the best solution so far: https://news.ycombinator.com/item?id=17496011. It would seem to have an obvious vulnerability: what if some users demand one change while other users demand the opposite change? Then we'd get a non-converging sequence and the objections would never subside. In practice, though, this almost never happens, and if it does then you can point out that it's happening and people will accept a best-faith arbitrary choice.
There's a deeper aspect too. The passion for titles is so intense that if we simply flex in response to objections, people feel heard, and immediately feel better. So it doesn't matter so much what the title edit precisely is, as long as it's good enough, because it demonstrates that there is an outlet for those feelings and that readers can actually affect the state of HN's front page.