Well, it is helpful, if you didn't grow up in the US listening to NWA and thus eren't aware that Compton's synonymous with "inner city ghetto".
But yes, there's a fair bit of useless "advice" on the site. It's human nature to try to be helpful, even when much of the advice offered is common sense. Hence this policy:
http://en.wikivoyage.org/wiki/Wikivoyage:No_advice_from_Capt...
As someone who isn't from the US, yes it is helpful, but that being said anyone who's used wikitravel/wikivoyage in the past would take one look at that page and realise that not many people visit and if they do they haven't found much to add to the site.
That's usually a fairly decent indication that there are better and more interesting places to visit.
WARNING: Compton suffers from a very high crime rate due to the gang violence, which is well-documented. It is recommended to stay no more than as long as necessary. Danger increases during the night time.
Helpful!