You can see Chrome devrels on Twitter expressing disappointment with Chrome-only web sites, saying that they raise the issue internally. Of course we have no visibility into what happens after that, but it's an indicator that you're right.
I’m guessing all of Google’s internal apps are only tested on Chrome, with plenty of Chrome extensions, which means that all of the developers have to use Chrome to make the tools work, and at that point, switching back and forth between different browsers is a pain so none of the other browsers get the love they deserve.
The attitude of “it works on Chrome, I don’t care about anything else” is fairly widespread anyway. Just to stem the tide a little bit I’ve been developing on Firefox and Safari first, and then checking Chrome last.
I got bitten before when I made a browser game, and then noticed that it was all sorts of broken on Edge, even though Edge supposedly had all the features I needed. It turns out that Edge did have all the features I needed, but I had accidentally used a bunch of Chrome features I didn’t need. The easy way out is to turn things off when I detect Edge. The hard way is to find all the broken parts and fix them. So nowadays, I don’t do any web development in Chrome.
At least in my part of the googleverse, we have automated tests running in all the browsers (even ie11).
But I'll admit I will also poke around outside of the tests, and I'll usually only be doing that in chrome, unless I've had a bug report about firefox in particular. And I'll only really open up Safari when I'm testing VoiceOver. ChromeVox just isn't good enough.
Oh, I’m sure there are automated tests. But if you have 50,000 developers using Google Docs in Chrome, they’re gonna submit some high-quality bug reports internally, whenever it breaks.
Considering that there's been an internal and external bug filed about the US states not being in alphabetical order on contacts.google.com for years, making it impossible to type 'new y' to get New York, I don't think raising it as an issue will help much.
