Talk formats do indeed lean older and more heavily male....i.e.: 65% male, 35% female, core audience 50-64...if a talker is really strong they do OK in 45-49, and most all talk stations really dominate age 65+.
The most desirable money demos for national and regional ad buys are:
#1-women 25-54 (about 60% of all radio ad buys go to this demo)
#2-adults 25-54, (about 20% of radio ad buys go to this demo)
...there's some dollars in 18-34 men/adults (beer, soft drinks, fast food)...a few teen dollars, and a very few 50+ buys.
Talk radio...especially with local hosts...is an expensive format to operate. And, whether the talk station is on FM or AM doesn't seem to change the core audience demo that much.
Talk radio's biggest problem is indeed the too male/too old demos to acquire big national/regional ad agency buys. And, radio is about making the maximum profit at the lowest-possible cost.
That's why it's often better to pick a cheaper-to-run music format who's core audience leans female, and appeals to listeners in their 20's, 30's, and 40's.