A bit of a side trek, but I wonder why the distinction between an explict label as an option and an implicit label as an option (say, as one of a list of powers which the player must choose from, and presumably cannot choose all from). After all, it pretty much boils down to the same thing in the end: either you or the people you are playing with at the table have it, or not.
It's different for my group, and many others, I assume.
From my experience, my players are perfectly fine with me saying "no druids" or "no bards" or "no barbarians" when we start the game; it's a sweeping campaign setting choice. They get a little iffy if I say "no Natural Skill feat", but they'll go along without too much fuss if I explain that I think it can make things overpowered; it's trying to stop problems before they start, and they appreciate the effort.
However, they question things a lot if I go on a line by line basis on what is or isn't an option; if I say "no, Bards can't get Cure Light Wounds" they'd question it, then question it again when I say "no, you don't get the Barbarian's damage reduction, you get this instead". These choices take away some player power (I'll go into that below), and in the Warlord's case (or others like it), one player taking one option alters how we all potentially play the game (where I don't run HP as explicitly luck and fate, and never as morale).
Now, in all of these situations, my players go along with it, because I'm running the game (and when I run the game, what I say goes; it's just my deal when I agree to run a game, and they know that and have no problems with that inherently). The reasons the last objections seem stronger has to due with reliable player control, in a sense. They don't mind me having the final say on what flies or doesn't, but they can't reliably build a class now without me holding their hand, because I have to say "yes" and "no" to everything I want in my game. This is why I like game systems with a "rule for everything"; yes, I can modify them, but it gives players an incredibly strong grasp on what they can do without permission from me. They can reliably make informed choices, and this last area takes that away.
This is a YMMV situation, but that's why I said it the way I did. It's not as big a deal at my table (where I say "here's the deal" and now that's the deal), but I still like letting my players have a reliable rules base for them to make decisions on, and having it be explicitly optional means that I don't have to objecting to a player making a decision that alters the very interpretation of the rules for the entire table. And, at other tables where there's a more relaxed "everyone decides setting stuff together", I would think a more explicit option for setting the interpretation of the rules (what HP means, and how it gets used in-game) wouldn't be a bad thing, either. That's just where I'm coming from, though. As always, play what you like
