So they can deceive the customer into thinking they will be buying a quiet car? It seems like there are enough reports of this to show that the car has a design or build problem. I never put my 2014 Volt into hold mode. I let it use up the battery charge first and then go into charge sustaining mode. I tried playing with hold mode when I first got it, using the ICE on the highway and the battery around town, but I couldn't see an improvement in efficiency. I know that theoretically it might be more efficient to do that, but I think the real life gains are tiny. And if I misjudge and pull into my garage with any charge left on the battery, I KNOW that I just wasted some gas and money.
Yes the Volt runs the engine at higher RPMs sometimes, especially when going up a hill, but it is comparable to a fairly quiet ICE car, not a luxury car certainly, but far from an econobox. One of the selling points of the Clarity frequently mentioned is how luxurious it fells. I certainly think it feels more luxurious than my Volt. Probably the main reason I am considering it is the seating is more comfortable and convenient (power seats). If I buy it and it sounds like angry bees or an econobox unless I manage the battery charge level carefully, I will be very disappointed.
Hopefully Honda can fix this problem with a software update. It seems like they could increase the battery buffer just a little bit and program the engine to run at lower RPM for a bit longer to replenish the battery. Hopefully that wouldn't decrease the EV range substantially.