This is true to an extent. However, switching algorithms and coin choices to make a big difference sometimes. ScryptGuild for example, has at least 2 coins they could add that would immediately increase profitability. ScryptGuild also, by my understanding, did not consider variable block-rewards when choosing what coin to mine - this certainly would have hurt the profitability vs say WafflePool by a considerable margin (there was some graphing done of these stats and it accounted for about a 10% difference in doge profitability while the block were variable).
I do agree the consistency of a pool's profitability is definitely dependent on the pool operator's active maintenance of coin choices, both the addition of good coins and removal of bad ones. I hope ScryptGuild doesn't end up a "set it and forget it" operation.
These are both good points, so I have to ask - what are these two coins, and when is Scryptguild going to get these two 2 coins put into the mix?
It's a little frustrating to think that my mining rig investment could be making (10%?) more money elsewhere.
What would be really great is if the operator of SG laid out a roadmap of future enhancements so we can see what is coming down the pipeline.