[kkirsche]

Can you elaborate on why this is surprising for those who don’t fully understand the differences?

[nasretdinov]

I don't think Multipath TCP has been tested in enough environments to become the default yet. It's compatible with TCP, yes, but it's mostly useful for e.g. mobile devices that have multiple links like Wi-Fi and 4G, and it lets users to maintain TCP connection to a certain service even when moving across networks. Go seems to be server-oriented first, and there are some potential downsides to multipath TCP in a datacenter environment (e.g. potentially higher CPU usage, etc).

[arp242]

"In a future Go release we may enable Multipath TCP by default on systems that support it."

This could be five years from now. Or maybe never.