And what about music composed without the aid of any instrument at all OR a computer? Joe Satriani did that with midnight and had to learn to adapt to a completely new style of playing in order to record it.
Or music composed for instruments other than the composers? Yoko Kanno for example composes piece for everything from synths to orchestras, yet she plays the piano...
That's just showing off!
Both of them are supremely talented musicians, both technically, (on their instruments), and in composing, NO ONE could deny that.
I'm not saying that playing an instrument isn't a worthwhile pursuit or skill, I'm saying that you are COMPLETELY missing the point of computer synthesis. The aim is NOT to reproduce sounds exactly, the aim is to make any sound possible given due care and attention. Although it can certainly be harnessed for such purpose, and programs such as Symphonic orchestra gold are, in listening tests, almost indistinguishable from the actual thing, a great advantage for those of us who want to add an extra facet to a song without having to hire a concert hall, mics, mixers, players, and then write the music on top of all that!
Having heard that programme in a studio, I think the word "Almost" is the one to consider, though I thoroughly agree your second point.
You treat sequenced music as if it all sounds like midi beeps and nes chips. It seems to me that rather than giving it a chance, you've let a presupposition completely dictate your attitude to something. Or, worse, you've let your original opinion on sequenced or synthesized sounds remain constant while the world has moved on and improved those technologies and invested more time and effort into them for any number of purposes.
I've played a number of sessions with the most up-to-date synths and sequencing, and still remain unconvinced.
As a classically- trained violinist and keyboard player, and a bass player and guitarist by preference, playing many different styles and genres of music, I'd hardly call myself blinkered to any kind of music - sure, like everyone, I have my likes and dislikes, but I think I can appreciate anything for what it is.
In short, I think you're just being foolish and trying to treat music as if it should bend to your whims.
Surely that's what every musician and composer does
Music has always evolved through technology, be it the movement from harpsichord to piano, nylon strings to steel, etc. None of that makes what came before any less valid but to dismiss a technology completely that is, with due time and effort, capable of reproducing ANY SOUND AUDIBLE TO THE HUMAN EAR,....
(.."trying to treat music as if it should bend to your whims" ????)... is lunacy in my opinion.
Yes, it can produce any sound, as you say, but where's the feel and the emotion - that's the whole point.