Do you often take blows to the shin or do you just prefer not to risk it? Shin guards aren't a question of fashion - they're a question of safety. Sure, they're a bit uncomfortable and can rub, but a fracture or serious shin contusion is way more than just discomfort from the guards. Young guys play without them because they're young and confident nothing will happen. But one unlucky contact with the ball or an opponent's foot - and everything changes.
After 15 years of playing, you've definitely run into situations where shin guards saved the day. If you're in amateur soccer and there's no real reason to get rid of them, then why would you? This isn't professional sports where every millisecond can be critical. Get yourself better shin guards - there are modern models now that are lighter and more comfortable than the old ones, don't dig in, and don't slip. Try a few different ones, and you'll find something that won't bug you during the game.