I was lucky enough to be using BOINC back when they had a deal with Ripple who were handing out free XRP to those who ran BOINC projects. The XRP I got are now worth far more than the GRC I could have gotten at the time.
Anyway, I'm mining GRC right now but overall this is far too complicated for the average user. We need to have something that is a one click install with no-brainer config and admin so almost any user can play with it. Basically as simple as the original SETI@home screen saver. At the moment on my Mac I'm always having issues with Boinc deciding to run computations when I'm using the system which can be super intrusive.
Although Gridcoin has a huge head start and a very dedicated community of users I'm wondering if you have looked Golem yet? https://golem.network/
I believe there are other similar efforts in the process - or at least where delegating CPU resources and even storage for distributed computation are a part of a larger system (eg. MaidSafe and eventually EOS).