Benefits are more marginal than a lot of people like to think. They are there, but they don't live up to the hype most portray. I'm not saying the CIC is a bad thing, it's a good thing, but that's just how it is. A place like JHU is going to look at the CIC and wonder whether it's worth the bother. They may very well join at some point, but JHU will see little benefit from it.
Edit - Let me expand by commenting on one of the key features of CIC membership - open library exchange. A friend who worked there recently told me, "Let me put it this way. When I worked and researched at Johns Hopkins, I never had to look for a single resource outside of their own library."
That is the state of JHU over everyone else. Their benefit from CIC will be minimal.
Library exchange is hardly a key feature of the CIC, it is a feature. I never used it either at OSU, don't know anyone that did (but I bet some of the professors and doctorate students doing research do), all the CIC schools have enormous library sources, it would be very rare that someone would have to look outside their own system, so the library thing is minimal if not nonexistent for almost everyone. In fact, I think every other CIC school has a larger library system than JHU (actually went back and looked, it appears only Nebraska and Purdue aren't, both Maryland and Rutgers are).
As far as school rankings (if one cares about that), two other CIC schools are ranked above John Hopkins and the other CIC schools start not too far away at all. But far more importantly, according to research university ranking data (here:
http://mup.asu.edu/), six other CIC schools are ranked in the top 25 with Johns Hopkins, with Michigan ranked ahead of them. The year before, two were ranked ahead and one was ranked directly behind JHU (none of these was UC). Why you would state "
That is the state of JHU over everyone else" is something I don't understand, nor does the data support the premise. Even the schools that JHU is ahead of isn't by much at all (like very little). Most of the CIC does more than the Ivy League (in fact the Ivy League has three schools in the top 25 research institutions, while the CIC has six). In fact, the more I look at the data, I am unsure what you are even basing your argument on. Maybe they wouldn't see the benefit from it, however, JHU is not in some pinnacle position that it cannot benefit the same as the other schools that it swims in the same pond with (again, with many CIC schools right there with it in research university rankings).
This all assumes a lot, but frankly, I have no idea if they would ever get an invite (I'm willing to bet the brass would jump at the opportunity, though). In no way am I saying the CIC is the greatest academic consortium one could imagine, but to say JHU has so much going for it that it would be minimal as compared to the other CIC schools just doesn't add up. JHU is in no way shoulders above the rest of the schools, and in fact is behind some of them. Again, the library thing means nothing, its just an added perk if needed.
**Edit: One more, just to reiterate, none of the schools in the CIC needs the consortium, it just flat out makes doing research easier, the benefit is there with no downside.