I agree with Dhugal. We are(were?) evaluating Sencha for a big project and that a seemingly official representative of Sencha was making those dismissive comments is disturbing and bad for Sencha's business.

Whether people like it or not, Coffescript, Typescript, and a whole bunch of other languages that compile down to Javascript are not going away. If COBOL was the only game in town for the browser, we'd be compiling down to that too.

If Sencha embraces these other languages, then they're more likely to not lose business when other toolkits come out for Typescript.