This just causes audience fragmentation and dissipation for no reason.
It's not for no reason. It's for the same reason as why I'm interested in learning what's new in .NET 4.0 and yet I don't know (or care about) why your printer doesn't print.
I like to have only programming related tags, users and reputation in StackOverflowStack Overflow. It helps keeping things more consistent.
Update. In Barcelona there are stores like FnacFnac or El Corte InglésEl Corte Inglés where you can buy music, dvd'sDVDs and books, among others. There are also book stores. And there are also technical book stores.
In theory, the general stores can have books about everything - they are well organized in sections and they have plenty of space in the store.
Now, go and try to find C# in DepthC# in Depth in El Corte Inglés.