I think Rand was thinking more about his own mental state and what the temptations of the Choedan Kal rather than the greater good that could be accomplished with it.

There is still the overall risk that they represent, though - with Circles, you at least need to convince other rational beings to Link with you to accomplish things. The concentrated power of the Choedan Kal, though, puts too much power into a single entity's hand, so I understand his decision.