In my group of friends and acquaintances, have quite a few electronic music producers. Most of them dont play any 'classical' instrument. Most of them can't even read music notes. They started producing when they were very young, from late 80s, 90s and some of them early 2000 time frames. Some uses samples of classical instruments in their tracks. Fortunately, most of the guys and girls I know who are producing, are not creating their tracks based on what is popular. They make what they want. Fortunately, some of them can do this and still make a good earning and still make a good earning, since they have a name in the industry and pretty nice fan base... But yeah, I also know those producers who create whatever is popular at that time. They not getting far, to be honest... More like 'one day flies'.

So I guess its the lack of exposure to the classical instruments for many electronic producers, not to include them in their work. For some maybe the time required to learn to mix 'old' and 'new', as you stated, it can take a lot of time to get it right.

Just keep on going! :)