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.  $72/month at most though.

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.