Everyone keeps telling "do not mine, it's not worth anymore". But why? I have been mining scrypt altcoins for 1 month now with 4 GPUs. The electricity is about 30-40% of the revenue, the rest is pure profit. I bought and built the rig myself. The GPUs are used ones, in good condition from e-bay. The whole rig costed about $1000. I earned 25% of it in the first month and planning to build another one next month.
According to my experiences is DOES pay to mine. It is not an easy work, fine tuning and continuous monitoring of the hardware is essential.
I do believe it's definitely worth it and a fun thing to do. Don't agree? Why not?
Maybe they mean don't mine Bitcoin. It's probably not worth it for BTC, but you can obviously make a bit mining alts and trading them.