I love wizard games, I love playing as a wizard and I love magic. That's why I bought the game. Even if the mana regeneration was terrible, if there was a way of increasing it without having to give up on achievements (which unlock character x class combinations), I would give it 5 stars.
You could say that's the dev's vision and how they want the game to be played. So, my family used to run a restaurant, and the best way I could compare the decision to punish a player that WANTS an easier/customized to their taste experience would be spitting on a client's food whenever they changed a plate. Oh, they don't like lettuce? Ok, I think this dish goes well with lettuce so I'll spit on their food because I don't agree with their choice and the restaurant is mine so I take the choices.
Sometimes I love gamers, and sometimes I hate them. And it also applies to devs. I tried to like the game, I tried every class possible (that had magic because I love it), and all of them felt bad for the lack of decent mana regeneration. If I WANT to play purely as a mage, then I should be able to do so. Call me a crybaby, but the real crybaby is someone that does not respect a client's preference and choice.
You could say "ok, so just don't play the game". That's what I did, after investing myself and really trying I just gave up. Even looked for mods that would allow me to increase MP regen, and just that. Didn't find em' so I just asked for a refund. And now I am telling you a game that would be absolutely wonderful for me left but a bitter taste in my mouth. Seriously, when people will stop treating devs like gods and simply have a mutual relationship of respect? Have a default mode and allow people to tweak stuff without shoving a knife on their guts. It's not hard, ok? Even easier than playing with low MP regen.