If one of these alt coins would actually give more than a day long announcement before opening up mining (as well as bring something new to the table), it might help. Lately it seems like the new coins just pop up like SURPRISE, someone is already mining 5000 coins per hour! SURPRISE, an exchange has them! Then they mine at 400% + value for 12-24 hours, the first miners dump their 5000 per hour on the exchanges at massive rates and get out, leaving straggler miners to try to pick up the scraps as the price drops below profitability over bitcoin.