I personally think it's fine as it is. We can do everything one one character, we have no need for an alt. So if someone wants to level an alt, then why should it get a level boost? It's a totally different character and they chose to create it... (and yes I have 2 level 50 alt characters that I level when I get bored).

Not to mention it could cause even more issues for housing (by making it that much faster for someone to be able to be meet the housing requirements and therefore easier for them to buy multiple houses, if there were some available that is...)