I blame George Lamb
More seriously, yes there is a case to be answered that 6Music is of interest only to 30-40-something yo blokes, but on the other hand it's one of the few music stations with the odd intelligent, knowledgeable presenter.
The BBC has also been told to refocus R2 more on the over 50s (read: over 70s), and R1 is targeted at the under 24s, so if 6 goes there will be a yawning gap in their demographic coverage.