Coincidentally it not being worth their time coincided with Mozilla not sponsoring the contest any more. You can make of that what you will.

Mozilla has never sponsored the Pwn2Own contest.

Are there historical records for number of "critical" vulnerabilities found in browsers? It would be interesting to compare the number for different browsers.

Update Maybe this:

http://www.cvedetails.com/product/15031/Google-Chrome.html?v...

http://www.cvedetails.com/product/9900/Microsoft-Internet-Ex...

Comparing the number of CVEs is not a good way to compare how vulnerable different browsers are. For instance, I believe that Firefox and maybe Chrome bucket together multiple internally reported vulnerabilities into a single CVE.

Don't do this, it's an anti-metric. Unless you think Opera and Konqueror are the most secure browsers.

That is a great argument against the monoculture seen in some product categories.

If (almost) everyone runs Windows you’re safer if you run Linux.

I heard a different story. Firefox was not at the contest because it was not in the same league as the others browsers (and not in a good way). See the last sentence of your link "We wanted to focus on the browsers that have made serious security improvements in the last year"

A rather arbitrary claim with nothing to back it up. For sure, Firefox made more security improvements in 2016 than it did in some of the years where they did feature it.

look here: https://it.slashdot.org/story/16/02/12/034206/pwn2own-2016-w...