No one has any room to complain if they prefer git and the shops repo is in SVN. The git-svn bridge is Excellent.
But if you're really good you might not be willing to spend a big chunk of your day fighting with obsolete technologies. Unless the money makes up for it of course.
I'm not fighting when I use svn, and it's relevant to the client. They choosed it because it's simpler for them, and do all that is required perfectly.
I would totally push git (I pushed for git in some places if you wonder) if I thought it would be a good fit for them, but it's not.