Older workers are harder to sweat.
Seriously, who's easier to con into doing 60- or 70-hour workweeks with no overtime pay, in exchange for vague, vaporware intimations of career success, bonuses, and fabulous stock-option payoffs? Fresh-faced, wide-eyed, wet-behind-the-ears twenty- and young thirty-somethings with something to prove? Or workers who've been around the block and have families and lives outside the company?
Implement mandatory overtime pay for all workers except for owners with a major stake (>10%?), and I predict that high-tech employers will suddenly discover that the experience and wisdom of older workers are worth something. Side Benefit: younger workers will very likely have more time for personal lives of their own when their every last waking hour is no longer free to the employer.