I don’t think any rider claimed to not use electronics. As far as I know, it’s not optional. A while ago, there was an interview with the riders of they would ditch electronics if they could. Unsurprisingly, the older generation of riders were of the opinion that they would prefer very little electronics if possible, but as long as they have to live with the current situation, they will. The younger riders said they have no problem with them.
Another article (I think on Crash) right after the switch to unified electronics said that when the factories had their own system in place, the level of control they had was astounding. Launch control for instance was refined to the level that all the rider had to do was release the brakes. The Magneti Marelli system was a lot primitive in comparison.
When the common ECU and software plan was made official, Ducati got a year’s head start by exploiting (rather disgracefully) the “Independent team” rule.
Honda hired engineers from Magneti Marelli who developed the unified software . Yamaha had previously used their hardware, but with Yamaha’s own software which means there’s very little to carry over. And they have a bit too much Japanese pride to ask for help, trying to do it all themselves.
To understand why some factories have an edge over others with the same ECU, read this:
https://www.crash.net/motogp/feature/895547/1/motogp-electronics-and-acceleration
It’s not an unsolvable problem, it just takes money, manpower and time to fix.