I'll admit to bias, because I am a professional financial advisor, but I'll make the case against index funds for completeness' sake.

If you have the discipline to invest a significant portion of your income, can weather storms in the market without panicking, and are in a simple enough taxation situation that you can figure out how best to shelter your income without needing professional advice, then you don't need an advisor. Empirically, however, most people do not meet this description. I know some who do, but a lot more say things like "I don't want to be bothered", or they have taxation situations that are complex enough they can't practically keep track(which is easier than it sounds - even having a company is more than enough to put you over that line), or they talk about how they sold all their investments and went to cash in January 2009. Active investments aren't terribly wonderful in their own right, but active investment with an advisor is empirically superior to passive non-advised investment for most people.

Also, the system does need some active management - passive investors are freeloading and not aiding price discovery, so if the whole market went passive then active investment would win handily. This isn't an issue right now, but it could well be if the passive school of thought gets much more prominent.