FormerlyHemlock
Hero
That's just it. Rarely is a non-battlemaster interested in taking the feat. And they've likely taken it after they've already capped their main stat and picked up a couple other, more desirable feats, as a luxury because the fighter enjoys so many ASIs.
When only one subclass wants a feat, that's a sign it's weak. Not Charger or Savage Attacker weak, but below average.
IMO, even if it gave 3 points and allowed you to pick any metamagic, it would still be weak. One quickened spell per day is not a particularly great tradeoff compared to +2 to an ability score. I don't think I would take it on my sorcerer until very high level, if at all.
It's actually more interesting on a non-sorcerer. A wizard with Careful or Subtle suddenly has new options and combos for avoiding friendly fire and/or illusion use, and 2/day is probably good enough if he uses them carefully.
I agree that it's about as good as Martial Adept, and I also agree that Martial Adept is pretty weak. It's a "fun" feat, not a powerful one. Nothing would break if Martial Adept gave twice as many dice; and nothing would break if Magic In the Blood gave twice as many metamagic options.