So I love the show. Shut up. Call me ghey if you want to; it actually produces legitimate talent.
But here's my complaint. Do I really need to see some 16-year-old who's voice hasn't changed yet belting out tunes in a singing competition? The show is wildly successful. They could do damn near whatever they want and still be number one in the ratings. So change your age limits to your biggest TV market goal: 18-34. Hell, even abolish upper limits. I know 40-year-olds that can sing better than these 16-, 17-, and 18-year old prepubescents. When they stretched the age limit to 29, they got Constantine Maroulis and Bo Bice. Skip the upper age limit and give us 30-somethings a go. I can sing better than 90% of those contestants (although I'm admittedly a somewhat experienced amateur musician), and am better-looking than at least 75% of the dudes. Oh, and I don't sing like a girl, either.
12-year-olds might watch the show, but they don't buy the products your sponsors are selling. They beg their parents; their parents say no. Stretch the limits, watch the sponsors' sales soar. At this point, work on the legitimacy of the competition. The older competitors are clobbering the teens.