While those cards may still be useable for mining, it doesn't mean they are still profitable for mining. You could be using more electricity to mine something worth less than electricity cost.
Are you trying to mine Ethereum? One possible reason for why you can't mine ethereum is because it requires GPU memory to be at least 3GB (google mining DAG size requirement). With those cards you mentioned i don't believe they have anything more than 2GB.
Well said, mining needs lots more to be into consideration. As mentioned electricity is one of the biggest concern that need to be considered before getting into mining. After investing into GPU mining my rig is still haven't started mining because of the increased electricity consumption charges which I never thought of before investing.