Sure, mainland doesn't usually produce "idol dramas," but they still have some, like the Butterfly Lovers, Good Morning, Shanghai, Bratty Princess, Warriors of the Yang Clan, and the Lotus Lantern.
But wuxia dramas are so awesome! Just because they were set in the old times doesn't mean they don't have drama, romance, humor, etc...and Jin Yong's stories are so popular in Asia!
They also have so many amazing historical fiction dramas based on real events, like Han Wu Da Di, Kang Xi Wang Chao, Da Zhai Men, etc.
So why don't people on the internet sub/watch/like mainland dramas?
This thread is so old, but I just wanted to say that Han Wu Da Di is a great drama! (I should probably check out Kangxi Wang Chao and Da Zhai Men, too. I've heard good things about them.)
I love mainland dramas because so many of them take the time to build up a very epic story. The long length really works to their advantage. Some other dramas I love are Qin Shi Huang, An Suan, and Shanghai Tan (only seen the newer version, though). Their endings are so bittersweet/depressing, though, so most of the time, I don't want to watch them because they're so emotionally draining.