Yes, they HAVE, in Cubasis even - and it was called "Voice Detective" @ the time.
They didn't leave it "built in" 4 2 reasons:
1) The net is crawling with "pitch2midi" and "wave2midi" converters in both hardware and software - even ReuvenM had a built such unit @ the time.
Manipul8ing such processing takes some skill, and so support must have been murder.
2) Midi is simply not good enough 4 drum replacements in 2DAY's style of recording, as I'm trying 2 tell U and as U're about 2 find out 4 urselves.
In the case of 80s snrs, with the sound emerging mostly from the "close" mic, carrying a mountain of reverb behind it, accuracy was not such a big issue.
So if U're covering "footloose" or just following the 80s concept , or maybe adding ambient sounds I guess U may get away with analog or midi triggering.
In the case of real-time per4mance (stage) it's a must ANYWAY. But ask any MIDI gtr player - MIDI is sluggish, and should b compens8ed 4.
2day's hi-resolution, compressed, in-yer-face, beat-detectived and sliced sound is achived with carefully placed mics, phase rel8ed.
The "snare" sound is constructed by adding sounds from all mics, not just a g8ed close snr mic, 80s style.
If replacing the drum's ATTACK in a modern hi-powered kit aiming 4 "that" sound - phase relations must b kept or the image will "change".
When a snr sample is ADDED 2 such kit replacing the original drum, SAMPLE ACCURACY is required - or else the sample will phase like a MF, and the drum's apparent level will uncontrollably fluctu8 due 2 the haas effect.
Furthermore, if the signal peaks r not aligned, then some hits will augment the drum's attack (punch), some will diminish it.
Single sample resolution means 1/44,100 (or higher) of a second, and MIDI is just 2 slow and coarse.
So OFF-LINE processing is preferred, and care is taken 2 verify that the "sample" is "phase locked" 2 the kit.
1 more aspect - Midi note velocity is represented by 128 values only - very poor if compared 2 the original's 24bit resolution. The snr dynamics would not b accur8ly reproduced .
And since we may b using GAIN TRIGGERED, multi-layered+random sounds (several snr hits ranging from low 2 hi and picked @ random 2 sound more natural) - MIDI leaves much 2 b desired
So that's what 2days plug-ins r about. It just makes no sense 2 use the older, slower and coarser standard, with such tools @ hand.
But hey - it's a free country, and that MIDI plug is free...