No of course it doesn't neccessarily mean that. Like most things in life; it depends. If you feel that your day job is fulfilling your interest and happiness as a developer, I'd say you don't need to work on side-projects, you're probably learning plenty during the day.
But if your work gives you restricted oppurtunities to try new technology, or burdens you with outdated tech and boring work, working on a side-project can reignite your enthusiasm in programming, which can never be a bad thing for your career.
Also, theres nothing to say you need to spend huge amounts of time on a side-project, maybe a few hours a month just to try a few new things. Sure, you won't become an expert in those things, but you'll get a feeling of what it's about.
And choose something fun to inspire you, nothing is more mind-numbing that coming home to work on a side-project that actually bores the hell out of you.
But if your work gives you restricted oppurtunities to try new technology, or burdens you with outdated tech and boring work, working on a side-project can reignite your enthusiasm in programming, which can never be a bad thing for your career.
Also, theres nothing to say you need to spend huge amounts of time on a side-project, maybe a few hours a month just to try a few new things. Sure, you won't become an expert in those things, but you'll get a feeling of what it's about.
And choose something fun to inspire you, nothing is more mind-numbing that coming home to work on a side-project that actually bores the hell out of you.