Flash is built-in to Chrome. You'll have to invent another straw man.

In fact, I recommend Chrome to unsophisticated users (hi Mom!) who need access to flash content. I tell Mom to never install anything ever. (She's managed to get malware on her Mac, even though I keep reminding her not to ever click on anything that says "your computer needs updates", etc.)

I don't think this would be that big of an issue really, because Flash is built into the Google build of Chrome. It's the one "extension" that would be really easy to give a free pass on this policy. This would probably be more of a nuisance on Chromium builds.

Technically, Flash is a plugin, not an extension.