Because they are using some proprietary technology that is only available in Google Chrome. It will probably take time for Mozilla to adapt this... When Google announced Inbox, they said it would be later adapted to work with other browsers. I guess it is not on the top of their agenda.
Funny, i just went to Google.com with Firefox. I see no messages. I also went to Google.com with Safari, and saw a message that said "A faster way to browse the web! Install Google Chrome"
I suspect a "This site only works with chrome!" message only applies to older versions of Internet Explorer.
Crying wolf is so boring these days.
edit: Also i find it hilarious that you think Google would risk rejecting all users who aren't using Chrome. Talk about a great way to give your Search competition a legitimate case.
edit2: The downvoting is cute, and i hope it's because of my tone and not me calling out lies. "Anything but Chrome!" he says - absurd. By all means, downvote my tone, but i should hope outright lying gets similar treatment.
> Funny, i just went to Google.com with Firefox. I see no messages.
I see it often on Firefox, I have the latest Firefox on linux (35.0.1). It's a blue bar along the top of many Google properties that are decently cross browser. Go to Inbox without chrome and you'll see the "only works with chrome" crap.
The biggest difference is probably NaCl in Chrome right now.
Then why have I begun to see "This website only works in Google Chrome, upgrade today!" messages all over the web?