I run Einstein because it is a good project and i have sparetime to share my cpu power. I support different projects through boinc and think it makes sense to support it without huge clustercenters.
The point is why not sharing your coumputing time to calculate interesting and innovative things. Hardly anyone needs the available computing power of his/her personal computer during web or office applications which is done most the time. So there should be more advertisments to share computing time for standard users.

Maybe the client should be more fast in reacting and scheduling if the PC is used, so the normal applications are not slower and the user has no disadvantage except higher power costs.