On OS X, go to the Chrome menu, select "Warn Before Quitting". This makes it so you have to hold Cmd-Q to exit. No more accidental closing.

This should really be a global setting in OS X. I find myself accidentally hitting Cmd+Q all the time, not just for the web browser.

A while back while looking for solution to this, someone told me a way to map splat-Q to "invert video," which is a great way of training yourself out of hittig splat-Q.

For quite a few users, OSX's entire concept of "quit the currently-active application" is downright archaic.

Do you no longer quit applications in [your operating system]? What's the alternative?

Neither Windows nor Android have a (generally-used) concept of quitting an entire application at the user interface level. You can force-quit a process, but that's a rarely-used feature intended primarily for debugging purposes (and accessible through a side-channel; Process Explorer for Windows, app settings for Android). Some applications implement such a concept, but they're generally "single-window" apps, where closing their sole view is equivalent to closing the entire app (games usually fit this category).

Nowadays, you can generally trust your OS to page an app in and out and devote no resources to it if the resources aren't needed. Quitting an app is for misbehaving apps, which isn't assumed to be the common case.

Install enough RAM to run every application on your system, simultaneously, without swapping...? I guess there's that.

I am surprised Apple hasn't encouraged users to do that, come to think of it.

That's the thing... from an architecture level, a modern Mac can already handle this. The fact that an app can have zero windows open (or minimized) but can be brought to foreground to interact with an app-level menubar attached to no window can be thought of as a bit of an anti-feature, depending one one's point of view.

For my work laptop, the same ~6–8 apps are always running. No need to quit anything ever.

At home, where I do a wider variety of things (coding, photography, video stuff) I do quit apps, but there's still a baseline of ~2–3 apps (Chrome + Music + one more) that are always running, which I would guess is pretty typical for most users.