It's difficult for a small community coin to grow if there is no "purge" event.
Yes I agree. What needs to happen is that a lot of these shitcoins need to die a death, freeing up the space for the good coins.
But - and this is the connundrum - as long as a coin is listed, it's alive and will be kept alive by various pump-and-dump artists. So really we need some of the exchanges to die as well, taking some coins with them.