WHOA there cowboy! No no no. First of all you don't know what subtle details might give away all sorts of things. Second of all and most importantly exactly what the lore is for any given monster is entirely up to the DM. The DEFAULT lore is outlined in PHB/RC, but a LOT of monsters have unique lore blocks and it is always up to the DM exactly what he tells and how he conveys that information in detail.
Stop trying to foist the DM job on the rules and then complaining the rules don't do a good job of it. If you want things exactly a certain way, you make it that way. The rules are there to give you good usable defaults and a framework, not solve all of your problems for you.
The problem is that many DMs follow the rules as written.
It's all nice and well to say "Well, the DM can change that", but many DMs won't.
Cowboy.

And no, I don't think that the Wizard from 100 feet away should know that the tiny little wand with runes on it is a dead giveaway for Fire spells instead of Acid spells. Or, spells at all for that matter.
I have no problem with monster racial knowledge. There should definitely be a rule for that. I have a serious problem with monster individual knowledge (i.e. this is a cutter, so he does this, this is a hexer, so he does that). This Lich casts fire spells and that Lich casts cold spells, based on their name in a book.
The very concept that a monster has the word "Cutter" (or even "Minion") in its name is illogical. That's handing out metagame information that the PCs shouldn't necessarily have and the real problem with this is that it is not an optional rule for lazy DMs, it's the default.
The default is the opposite of what you just stated. The default is to make the game easier for lazy DMs. Stop trying to foist the DM job on the rules because that is what the default does: giving out the PC (and hence player) monster knowledge with a roll as opposed to giving it out with a DM description.