Truthfully, I don't think 'proper' touchtyping is necessary, per se. I type without looking at the keys, but I only use - I think - three or four fingers of each hand, tops. No doubt proper touchtyping would be more natural for me had I learnt it from the beginning, but I haven't, and trying the proper way hurts my hands after a few hours. I'm able to keep up 100wpm with ease just by having typed a lot in my life. I don't think I'll ever need to type faster than that. Thus, I don't see a reason to learn to touchtype.
Also, I've always disliked those exercises where you have to type jj ff jj ff jj ff jjf jfj ffj fff fjf etc. etc. One of the reasons I can type fast is because I like to hold complete sentences (or blocks of text) in my head and then WHAM it all in on my keyboard. With these exercises, there is no such link, and I have to look at each specific character on my screen. It annoys the crap out of me.
Those exercises are just building muscle memory, so that when you get to complete sentences you don't have to look at the keyboard.
There's a niche in the market for a product that helps people unlearn poor habits and retrains them to use the correct method. (If those people want to. I agree that you have no need! I also find that my arms hurt if I use the correct method.)
Also, I've always disliked those exercises where you have to type jj ff jj ff jj ff jjf jfj ffj fff fjf etc. etc. One of the reasons I can type fast is because I like to hold complete sentences (or blocks of text) in my head and then WHAM it all in on my keyboard. With these exercises, there is no such link, and I have to look at each specific character on my screen. It annoys the crap out of me.