Workers probably can't do much to change an established company dress code one way or the other. But the one thing you do have control over is preparedness.
Ask about the dress code during your job interview. If you're the kind of person who swore he'd never wear a suit and tie to work every day, then a formal dress code is something you should know about up front. Not only that, asking about the dress code also gives you an idea of the company's atmosphere in which you'll be working.
But most of all, trust your gut. Take cues from your boss and your co-workers, don't look like a slob if you have to meet with a client or company executives and leave the Guns N' Roses Appetite for Destruction tour T-shirt at home. When it comes to dressing for work, a little common sense goes a long way.