It's a hack, sure, but it's necessary if those small projects don't want to put up an official site or host on S3.
It literally costs cents for S3 and they offer a 1 year free usage tier for new signups. S3 or proper hosting is definitely the way to go.
For one it may amaze you, but some people actually pay for Github. Those same developers often have their own hosting (I personally have 3 linode vps's active for various projects)
The fact is it was just simpler as the maintainer of an Open Source project with numerous contributors to host it under one roof, all the contributors have their access granted in a single place, one set of keys to set up, one account to manage personally, and a single place to go look for X.
I am sure you love github and all, but I assure you you arent helping them by before anyone had even mentioned a word, insulting everyone who dared to voice an opposing opinion to this change, then continuing to do so in follow up comments.
Again, this change may very well be in github's interests, but it's also going to make life more annoying for many gibhut users.