What I’ve found (in multiple systems across different companies) is spells and other class abilities that are in any plentiful amount will eventually have duds in them, and eventually printing schedules means you can’t fix/test them all. So you send them off, hope they don’t break the game, and make errata later if they are truly broken. This is a case where they had time to fix them, eventually.
He was also constrained by some of the history of the game. There have always been spells in D&D which are better or worse. It’s become a bit of a joke that the first spell taken by any wizard is Magic Missile. Why? Because it’s been one of the most useful 1st level spells for wizards since early D&D. So, into the spell book it goes, and it was very often the one spell a first level wizard memorized.
I’m just glad that the designers are willing to take a critical look at their own work and say, “you know what, this sucks, let’s fix it”.