Li Shenron
Legend
I just want to say that I am a big fan of restrictions such as the Paladin's Lawful Good requirement and the elf only Bladesinger, for example.
In my opinion, restrictions give certain things that touch of specialness. I don't want a game where everyone can have anything. I want alignment restrictions, I want feat restrictions and I want class restrictions.
I don't want a generic game where everything is a free for all.
Half of the gamers want and need restrictions to avoid a kitchen-sink type of game, but the other half hate restrictions because they don't want to feel limited or constrained to a type/style/flavor they don't particularly like.
It should be clear to every non-beginner gamer, that a RPG is MEANT to be customized. The problem is that what is written in the core has a certain aura of authority that sets expectations to everyone playing the same edition.
I think the best thing they could do in 5e is to make it clear: if they use a default setting (which I am not in favor of, but I think this is what they'll do) then they should WRITE it explicitly to every restriction that it is because of the setting. This way, it is immediately evident that it is a suggestion only, that will be probably the starting point for everyone trying out the new edition, but also that it can be easily lifted as soon as the group goes homebrew or modifies the setting.