Truth is, most of the altcoins created are just clones that don't really offer anything useful. The only real alternative to Bitcoin is Litecoin.

You're just singling out Dogecoin because it became popular. And speaking of popularity...

The popularity of Dogecoin has done wonders to increase awareness of cryptocurrency. For many people, Dogecoin was the first cryptocurrency they've heard of. As we know, any money system can only be successful if people use it - and Dogecoin has definitely made Bitcoin more popular. If you want a currency like Bitcoin to become accepted globally, the general public has to be familiarized with it.