Why hasn't a pool owner modified SHA coin clients so that all SHA coins can be merged mined at the same time?
There are a lot of very intelligent people in this forum and it appears that this is a feasible task.
So why hasn't it been done?
maybe because all ALT SHA coins are even less profitable then BTC?
I understand that but if you could mine multiple coins at once using the same hash power, then you only increase profitability.
Barely. These coins are worth nothing, if you start merge mining then, you'll increase difficulty and the profitability increase won't even cover costs of running additional software. That's why almost no pools mine anything except for NMC.