Bruce, I agree with you. And as a composer, I find it much more satisfying and enjoyable being able to work this way. Staying up all night to copy parts after you were exhausted from writing so you could hear a bunch of students make a mess of it was never all that much fun (well, it was fun, but it had serious drawbacks). There are ten billion reasons why samples and synths are a great thing, and I agree with all of them (because I love the medium). The most important one is that a lot of music that would never get heard otherwise is being created.
However, the argument to what you're saying is that close as you can come, there's nothing like a real orchestra. It would be sad if bow-scraping and razzing into plumbing, etc. became a lost art. There aren't enough orchestras to support all the great players around now...and in fact the audition process favors young people just out of school who have been doing nothing but practicing the audition literature all day long; older musicians who play with more depth because of all their experience are at a disadantage.
So how are those cockroaches going to adapt?
I'm not saying you and I should look back, just saying that I can't dismiss the discussion as easily as you can!