There is a learning curve on all software, and the more complex, the longer it is. The software on the iPad/iPhone is consumer level, low complexity. I don't think most of us have previously used software with the functions provided on typical EMR programs. Once you add in the factors of networking, different hardware, etc., support is a good option to have.
Most of the larger vendors charge several thousands of dollars at start-up just for training on their EMR, and many hundreds per month for support. So the AC charges are very modest.
As for Microsoft, a better comparison would be server software for a network. You will need support, and you will surely pay for it!