If your only experience of OSS was Richard Stallman, you might dismiss everyone who contributes to open source software as a bearded lunatic.
There's a lot of very serious and studious Pagans out there, but they don't tend to be as obviously 'look at me, I'm SPOOKY' as the kids you're talking about. For a trivially easy to find example, consider the Pagan Federation. In Scotland they work with government interfaith groups and are consulted for things like religious diversity training material and non-denominational chapels in hospitals.
Most Pagans I know look a lot more like RMS than someone who shops at Hot Topic.
I guess my other problem with neopaganism is the same problem I have with all new religious movements. Any religion is irrational, but older religions at least have the excuse that you were likely born and raised in them, and the wider society may in fact pressure you into taking them seriously. If you're nonconformist enough to reject traditional religion, being taken in by nontraditional religion makes you more of a mark than the typical Christian.
There's a lot of very serious and studious Pagans out there, but they don't tend to be as obviously 'look at me, I'm SPOOKY' as the kids you're talking about. For a trivially easy to find example, consider the Pagan Federation. In Scotland they work with government interfaith groups and are consulted for things like religious diversity training material and non-denominational chapels in hospitals.
Most Pagans I know look a lot more like RMS than someone who shops at Hot Topic.