The advent of computers also killed one of Dvorak's selling points, which was a lower error rate at speed. Errors on a typewriter were painful to correct and took up a lot of time, but by the 70s and 80s, even typewriters were capable of reasonably easy correction. By the time word processors kicked in, mistakes were nothing to deal with.
OMG no it does not, your argument is ridiculous. You have to learn all the fingers and then all the keys before you can touchtype, no matter what layout you are learning. You can't efficiently touchtype 20 letters of the alphabet then take your hands off to hunt and peck the rest on a dvorak or a qwerty.
What letter you are instructed to learn first is immaterial. (and in GP's example, since I was taught by the same system, you don't learn semicolon as your 3rd letter, he just threw that in; you learn to rhythmically intersperse pointers (index fingers) and thumbkins/space first, then you add in tall-men, interspersed, etc. then moving between rows.)
what you are trying to connect your argument to, unsucessfully, is the idea that index fingers are naturally the best typists (coordination, musculature), so "let's give them the most common letters to type", which dvorak does. But this also implies, btw, that your worst finger, pinky, will over time also get the least exercise, so the gulf between its skill and pointer's skill will grow, not shrink. (I'm not saying that's more than a 2nd order effect, just sayin, muscle memory, 10,000 hours...)
Being able to type many words from the "home" keys (AOEU HTNS) neatly demonstrates this.
That nicely demonstrates the poor Qwerty layout. The very first keys you learn are among the least used, especially semicolon. Adding the left hand (ASDF), we can then type 44 words from /usr/share/dict/words, like "salad", "salsa", "flasks", "falls" and "alfalfa".
For Dvorak, the instructor would be calling out "H-H-H Space, T-T-T Space, N-N-N Space, S-S-S space" — and then U-E-O-A on the left hand. We can already type 467 words! So the instructor would soon be calling out "Season, Tenant, Hushes, Taunts, Outset, Sunset, Assent".