There are thousands of people in every town who used to write songs, play in bands and dream about making a living in music someday. Days pass, then years pass. Life gets busy, and life moves on. It's tough for anyone to earn a living solely as a musician, and it's tougher still for those thousands who never had the dedication or luck to find a career-building breakthrough.
Still, music-making doesn't have to end - though it usually does. Maybe people think it's undignified or uncool for a middle-aged man to write and record rock songs with no guarantee of anyone hearing them. If that's the case, they're missing the point. Nobody listens to garage bands of 18-year-olds either, but the 18-year-olds don't care. Age shouldn't change any of that. It shouldn't even mean that the music is less relevant than anything that did "breakthrough." It doesn't mean it's better than anything else (of course) - but new music can be relevant, even if its audience is really tiny.