In terms of the ratio of Linux distributions which use Bash as the default shell versus those that do not, the vast majority still use Bash.
Even if this is true, and no I haven't checked it, it has no relevance over the reality of how many people are effectively using Bash together with the Linux kernel, which is a matter of which distributions people effectively use. I do aknowledge that RedHat-derived distributions are probably more common on servers, but I'm just guessing that out of prejudice.
Debian-based distributions use dash as the default system shell, but Bash remains the default interactive shell,
If you really had a server of any kind which spawned a *real user login shell* as a result of a remote client request of any kind, then you would already have a huge security problem. Moreover, I expect lots of people will use Bash as their persoanl shell even on BSDs as it's so much better than Tcsh.
and many scripts specify #!/bin/bash in their shebang line.
Then they are as broken on FreeBSD (or any other OS) as well as they are on Linux distributions that haven't Bash as the system shell.
That last bit is important, because we're living in times where an increasing number of developers are releasing code for network daemons which are designed to be easily run under unprivileged user accounts by those same users. Regardless of how secure the daemons themselves may be, the simple fact that they're executed with Bash as their parent process means they're vectors for system compromise from bugs like Shellshock.
How so? The bug is triggered when you start a buggy Bash shell having a malicious environment variable set up by the parent. Having Bash itself as a parent isn't a problem, because the bug is triggered when the environment is parsed at Bash's startup time (the shell might even crash afterwards).
The karma bonus posting option is enabled by default for a reason. When people who have an established track record of saying meaningful things (as determined by the up-modded metric) post comments, those comments are automatically ranked higher. Likewise, the moderation system provides for down-modding of any given comment, which has the side effect of karma reduction for the "offending" poster. The fact that you don't like what someone has to say is really of little consequence unless you have mod points; this is by design.
The karma bonus is there as a measure to let *you* moderate your own comments. If you consider 2,000 characters of condescendension as something that is worth promoting, good for you, but don't expect other readers to share your conviction.