Yes. If something is difficult to install, even to evaluate, then people will not put forth the effort to try it out.

Their market is pretty niche: people who like GitHub, but don't want to pay for private repositories or need to host it themselves without paying for GitHub enterprise (or have some other need to host things themselves). So, they need to target developers who may or may not be familiar with sysadmin work. On top of that, their installation requirements are pretty specific, so if you don't have a system (or VM) with those settings, you're pretty much left to your own devices.

So, yes... I think 90% might be a reasonable number here. It might be a bit high, but it's in the ballpark.