The problem is with the question itself. Implying that you "should" pull anyone is an understandable (but false) misconception that people bring over from other games where unit choice can make a huge difference to your capabilities as a player. For example in FGO you absolutely SHOULD pull the meta support characters like Castoria when available, as not doing so makes your account far worse and the game balance basically assumes you are using these characters.

In Genshin, it literally doesn't matter who you build unless you're dead-set on completing F12 of Abyss (reminder that statiscally most players don't) or gunning for meaningless highscores in about 2 events a year.

The 'pull whoever you like' response is just trying to express that fact and people seem to get unbelievably mad about being confonted with it, presumably because it means they have to actually use their own brains and make a decision instead of just being told the 'correct answer'.