No.

300MH/s = .67BTC/day
= $5.70/day
= $171/month

And anyone with that kind of MH/s is probably using no more than 250w of electricity, so 180kwh/month, or about $18 more in electricity per month.  Well, if you get decent rates on electricity, anyway.

Mining is far from being unprofitable.  When difficulty hits 4M, then we'll talk about it being unprofitable for a good portion of hobbyist miners.