Feel free to listen to the context at https://learn.microsoft.com/en-us/shows/lang-next-2014/from-... around 20:40 to 21:10. It's pretty clear that it's a serious quote and not "sarcastic" at all. Least of all about research languages since Pike mentions CSP at length and how to make concurrency be not "scary" to prospective users - overall, it seems that he's talking about a real constraint he's facing. In the same talk he's even apologetic for not preventing data races in the language, since it would have involved too much complexity.