5 reasons you should not ditch Windows:

• Your hardware is incompatible or you do not want to fiddle with settings or command lines

• Your applications/games only work well on native Windows (and not wine)

• You need serious group policy support or other device/software lockdown methods

• Your company policy requires it

• Makes helping Windows users harder if you cannot walk them through the same things they are doing

Of course if any of these apply you can always dual-boot or use a VM. I'm not saying you shouldn't use Linux at all.