In a different context - teams of software developers - we say that we're siloing. For example, we have a team of Windows and Mac developers, but the Windows folks aren't doing anything to participate on the Mac side, and vice versa, so they're forming silos. The idea should conjure visions of grain silos. A farmer might have a corn silo and a bean silo, and certainly wouldn't want the contents mixed. In software development, siloing is considered a Bad Thing, or process smell and we might counter it with (again, thanks to the farmers) cross-pollination.
I haven't heard it used outside the software development context, but it seems like it would be a perfect fit for the situation you give, and has the appropriate negative connotations.
The downside is that your audience is probably not all software developers, and they won't know what you're talking about.