The older a character, the harder it is to make him/ her sympathetic despite a flaw, because that flaw is part of the character. Few people change in any fundamental way once they’re in their 30s and beyond. Their character is set: that’s just the way they are.
Your readers can empathize with a man who’s hot-tempered in his 20s, and gets in trouble because of that. Once he’s in his 30s, that flaw probably won’t work, unless he’s well aware of it, and is actively trying to change.