Do any cultures disapprove of meditation?

Answer 1

That would depend on the concept of meditation in question. In the Catholic tradition, for instance, meditation is supposed to be centered on something (the contemplation of the life of Christ being the most common example) and other traditions of meditation which involve emptying the mind in order to achieve an altered mental state are frowned upon.

Another Answer:

Well, actually, another theory about meditation, though not really addressing the question...

Emptying the mind is a known method that works for a lot of people. One opposing theory, however, is that we are all psychic, and that we simply hear each other's thoughts as our own. Those considered psychic have learned to tell the difference. Those going "crazy" are those that are unable to shut the flow of thoughts off.

Given that as a hypothesis, it is interesting that "meditation" involves stopping all thoughts. What if, in doing that, you were shutting out the thought stream that you were actually looking for? Interesting...

Back to the question, though I am by no means an expert on this, I would think that some religions may frown on meditation because in emptying your mind and allowing for the possibility of new thoughts and philosophies, you might, just might, be opening yourself up to demon possesion. From a "conspiracy theory" perspective, yet another way to look at this, opening yourself to other ideas might allow you to know the truth, and some religions will stop at nothing to prevent one from knowing the full truth about anything. Hmmmm....