For me manually switching shutter modes from mechanical to electronic to get a shutter speed I want is just one more thing I'm potentially going to forget to do and at best one more thing I'm going to have to do before taking a picture. Many will not suffer my ocd and irritation over this and might find the following statement hard to believe as I use manual lenses so much...
I mostly want the camera to just get out of my way and let me take pictures.
To me having to manually change a setting is the camera getting in the way. Having said all that for the pictures I take, mostly static or slow moving, the electronic shutter might well suffice but even if it would I'm being forced to use it and at some level that triggers me and of course some people will run into issues with the electronic shutter with moving subjects.
All in all I'd much rather have a shutter which goes to at least 1/8,000 together with lower than ISO 100 values being available to include in auto ISO so that I don't have to select ISO 50 manually (it's just another thing to do and another thing to get in my way) when running into the buffers at 1/8,000.
The last time I went out for a day it was to Whitby and I think I took in the region of 50 pictures two of which needed me to manually select ISO 50 and another one was taken at ISO 100 with a shutter speed exceeding 1/4,000. Some might not see having to press a button or otherwise change a setting 6% of the time a biggie but I see it as a needless limitation which could potentially go away if someone at Sony typed in a few more lines of code and made lower than ISO 50 ISO's available in auto ISO. I have tried just shooting at ISO 100 and trying to reduce the exposure post capture but shooting at ISO 50 to drop the shutter speed seems to give results I can not match when shooting at ISO 100 and trying to pull it back post capture.
Anyway. Ignore me