The point of a CTO talking up one technology or talking down another has absolutely nothing to do with swaying your ideas about that technology at all.
A CTO isn't a technology evangelist for or against that technology. The role is to get the most out of whatever technology the company is using. If talking down weaknesses in one technology and talking up strengths in another helps find hires looking for the technology the company is using or shows the strength of the company in being able to address those weaknesses or take advantage of those strengths, then that's good for the company.
CCP Games is probably certain someone else can do without Stackless Python. The folks at Facebook don't care if you use PHP or Hack at some other company. Booking.com is perfectly happy for you to use Python, Java, Forth, Haskell, or whatever at your company but they sponsor Perl conferences. Those companies will continue selling their in-house stack and its advantages. They'll continue pointing out where one solution grew creaky and they improved it with something else (like Facebook and Hack). They do that because it's good for them.