No one should have to convince you to solo mine.....  if you have to ask why should you solo mine instead of a pool, you haven't done your research and reading to understand the differences between the two.  With Solo mining you could find a block in a week, or never.  

Mining in a pool is like saving your money in a bank account....  solo mining is like taking that money and going to the casino to make 10 times that..... greater risk, greater payout or nothing....  if you like to gamble try solo for a couple of weeks.... if your conservative... stay with the pool.