In at least one study[1], admittedly funded by Sanofi, ~1/3 of people stuck the wrong end into their thing and ~1/2 didn't keep it in long enough. Just to emphasize on the second item, you said "count to 5" when the EpiPen instructions say 10 seconds. Only 35% of people completed all the steps correctly.
[1] http://www.jaci-inpractice.org/article/S2213-2198(13)00125-6...
Ow...
2. Except you missed a step - you have to take off the cap AND the safety. I don't need an EpiPen to tell me how to use it, but if my son is anaphylaxing, I want a panicking 15 year old babysitter to have a device that is as fool proof as possible.
In an emergency situation it's occasionally other parties, with no experience or knowledge of these devices, who administer. The design decision was likely made for observed reasons.
Oh wait, it talks to you. Why do you need an EpiPen to talk to you? You literally just take the cap off, whack it to your (or their) thigh, and count to 5.