Scrypt mining on GPUs is not profitable for last 4-5 months and only way to make ROI was to mine the newly launched coins and sell them on exchange faster. But there is shortage of good coin releases lately and ROI on GPU is much more difficult.
That's why it's better to mine cpu only coins. GPU mining has no profit at all.
GPUs can not only mine Scrypt. There are many other algos out there.
If you mine coins based on other algos on gpu it would be still unprofitable, IMO