Such "philosophical" threads appear in whatever subforum irrespective of the existence of the Philosophy forum or not.
Again, crackpottery was NOT contained to the TD forum in its time, the whole forums gained, as a whole, from removing that forum.
there will always be a trickle of crackpottery into PF, but shutting down Philosophy cannot be expected to increase that flow by "too much".
The reason for that is that normally, threads of that kind will be reported and deleted immediately after its first post, without anyone getting the time to wind up the "discussion", something OP will find sufficiently frustrating so that he gives up and goes somewhere else.