In my experience, there are a number of users -- GekoCH here for example -- that like to stick with earlier versions of Arduino. There are a number of "stale" libraries that no longer work on the newer Arduino versions. That's frequently the motivation for staying with one version. Is that the case here, GekoCH?
When these users try to deploy certain newer libraries like NewSoftSerial, they get these cryptic error messages. Then we get thrash on the forum as the well-meaning library writer tries to make sure his users are happy. 
If I had been able to deliver a succinct #error "This library requires Arduino version X. Please update." I think some thrash could be avoided.
Thanks,
Mikal