The idea is that you don't need a lot of money to mine . Anyone who has a gpu  can mine ( which is any gamer , or most people with a computer ) Asic's are specialized computer with one purpose ( to mine a specific algo) , they are expensive and can only be used for that purpose. Only a few companies make asics , so coins that use asics are at the mercy of said companies to make asics and better asics every so often .The main problem is that some, if not all asic companies build asics and use them until they pay for them selves and then sell them to the consumer when it's very hard to make ROI on them .