In which case, I'd encourage you to find some other way to demonstrate that value. E.g., blogging about your work. Beefing up your LinkedIn resume with testimonies from fellow engineers. Making an interesting toy project that you can publish.
If you want people to see your value, you'll have to find a way to show it to them.
Heh - probably. But I'm far too self-conscious to have a real blog for people to read, especially considering how harshly I judge other people based on their blogs... and think how it makes them look like arrogant pricks who I'd never want to work for.
I have a measely 150 rep on stackoverflow, have a long-dormant github account, and I don't know what Quora is. But I've worked on some interesting R&D projects over the years, and have written some fundamental code that will stay at my organization (an R&D lab) for a long time. In short, I think I'm a valuable person that is in no way reflected in my github/stackexchange accounts.