This may be a transient problem as people get used to new technology. It's like using Filmlook to put scratches and grain on HD video.
The 2013 Lotus Evora, a series hybrid vehicle with an electric motor and a fixed gearbox, took this to the point of silliness. Not only did they provide fake engine sounds, they provided shift paddles and required the driver to shift software-simulated gears. They even provided a momentary loss of power during simulated gear shifting. (http://www.autoblog.com/2013/01/22/lotus-pondering-fake-shif...) The driver could select different sounds, or turn all this off and just let the electric motor do its thing, which yielded better acceleration. Here's a demo of all the sound options: (https://www.youtube.com/watch?v=H1CzoqEyACQ). Options include simulated straight-6, American V-8, and V-12 engines, plus some turbine-like sounds.
After some snickering from the automotive press, this feature was dropped from later models.
Many electric cars already have an outside noise generator, mandated by law in the EU and US. These switch off above 25 MPH or so, so they don't contribute to freeway noise.