I've described several oddities about how you can Follow a blog - the different account hosts that you can use, the different profiles that you can use, and (in some cases) whether to display an individual blog in the list of Followed blogs for the profile used, or even to allow access to the profile used.
There's a lot of choices there, and not everybody understands all of the implications for the combinations of choices. Take a look at the Following community for any blog with any interesting number of Followers. Let's use my Following Test blog, in this case.
Look at the first named icon, in the gadget for my blog - see my icon? Watch the popup when you hover the mouse over my icon, and you'll see my name, "Chuck". Click on my icon, and look at the profile displayed. The profile name "Chuck" is blue, because "Chuck" is a link caption. The target of the link is my Blogger profile, because I am Following that blog, using my Blogger profile. If I was Following the blog using my Google profile, the target of the link would be my Google profile.
Not all Followers profiles, displayed in the Followers gadget, provide a link to a profile. Go back to the Followers icons, for my blog, and go two rows up from my profile "Chuck". Look for the giraffe, with a popup of "nitecruzr". Click on that icon, and look at the profile displayed. The profile name is, of course, "nitecruzr" - but the profile name here is black, because "nitecruzr" is not a link caption. I Followed my blog as "nitecruzr" using my default Following profile.
When you Follow a blog without linking an external profile, you use a default Following profile. You can edit your Following profile using the Settings wizard. If you see "Already have a profile on the web? Use it instead", you are Following using the default Following profile. If you use your default Following profile to Follow a blog, your Followers display will not link to your Blogger or Google profile, and the profile name won't be clickable. You'll have a few basic settings to make there, in the Settings wizard, and that's it.
So, when you look at a Follower, and the profile name isn't clickable, that's probably because the person Following is using the default profile, for that blog. That's his or her right.