Chrome has been the new IE for years. "just use chrome" is an endless refrain from webdevs who don't want to test on Firefox. Not sure why it is so hard for people to see what is going on here. Google has a massive conflict of interest with their web development efforts. This is classic Microsoft-esque Embrace, Extend, Extinguish.
I develop in Chrome because that's where the majority of our conversions come from.
I (my QA team) also tests Safari, Firefox and other browsers where a significant number of conversions come from. I never heard "just use chrome" in any professional environment.