It's amazing how often the "we're not a software company" phrase is bandied about. My employer has been around for a while, the IT department has over a 30 year history. Yet, we have the phrase repeated to us whenever we discuss using source control, developing libraries, having a web services strategy, etc. It is like saying, "We're only a youth hockey team, not a professional one, therefore we don't need to use the same equipment and strategies as the pros."
Just because you're not planning to be [put your favorite professional software company here] doesn't mean you should avoid learning their strategies for dealing with everyday problems associated with writing software - unless you don't write software at all.
In the end, the phrase is nothing more than an excuse for avoiding the risk of cultural change.
If you're working at a software shop that doesn't even use source control I suggest you get out of there ASAP. It's one thing to be missing core tools and methodologies when you're applying for your second job 1-2 years in, but if you hit the 5 year mark and have zero familiarity with source control or web services (for industries where this is valuable), etc. you're going to get passed over for interviews. Staying there may be causing irreparable damage to your career.
Saying you shouldn't use source control because you aren't a software company is like saying the janitor shouldn't have a mop because you aren't a cleaning company.
Just because you're not planning to be [put your favorite professional software company here] doesn't mean you should avoid learning their strategies for dealing with everyday problems associated with writing software - unless you don't write software at all.
In the end, the phrase is nothing more than an excuse for avoiding the risk of cultural change.