This dances around the part everyone dances around.When is a problem a rules problem?
I think this question plagues this community, on this forum and beyond. Many issues are misintrepreted as being rules issues when they are not. An example would be a background that gives a feature, one with no hard mechanical benefit, being ignored or made useless by a DM. This could be attributed to a rules shortfall, a balance issue per say. But in reality this is a DM issue, one where the severity varies by player expectation.
In this case we have a spell with a open ended spell description. If that spell causes a prolonged rules debate, is that an issue with the spell? Or is that a DM issue as the prior example was?
My inclination is that both of these are DM issues. I think hyper-specificity on rules hems in games with good DMing to prop up those with bad. Removing options from players in an ill-fated attempt to "fix" bad DMing. My biggest fear in this hobby is that we "rule" our way out of dungeon masters and into a video game, and sadly this is a small step in that direction.
Expectation.
Alice, Bob, and Charlie expect different things from Command.
Times that by 100 with this game of 500+ spells.
No way am I gonna discuss 50 spells every Session Zero.
This is an inherent issue when you have a large diverse audience/customer base.
Smaller games have smaller self-selected demographics who have similar expectations from their spells.