Sel-employed

Why can I put more money each year into a 401(k) than I can an IRA? This is stupid. I'm currently a contract employee and can only put $6,000 a year into an IRA, since I'm 50 and can use the catch-up provision. Last year, as an employee of a company that offered a 401(k), I saved more than $12,000. Plus, my company matched very generously. Thanks, Ernie, Sunnyvale, CA