If your middle and ring fingers are not strong enough to push the buttons, you need a better keyboard.

In all seriousness, though, I personally don't like having to reach with my index finger to move left. I tend to think of 'jkl;' as being a more efficient set of arrow-keys. (Where, with the arrow keys, your index finger goes left, ring-finger goes right, and middle finger goes up-down).

If you can hack it with 'hjkl' more power to you, but I found it extremely annoying to have to 'reset' my hand position every time I wanted to type text in insert mode.