Personally, I think a 4 stroke is just more "pleasant" in the types of places we would tend to fly float planes.

I know myself, I'll be flying off a beautiful mountain lake, with fellow cottagers all around. This environment is much more sensitive to objectionable noises than a regular flying field in the middle of farmland. Most people find 2C engines more objectionable than 4C engines, both in tone, and volume.

Motorcycle and Snowmobile riders are learning a hard lesson that all those years of running open pipes... might not have been such a hot idea. There's a whole lot of momentum going to ban these vehicles from just about all wild areas.

If we want to continue to have the freedom to fly in areas like this (as I'm sure many of us do), then it's best to use 4C that aren't as annoying to others in earshot.