Many people have answered your comment, but I don't think any of them actually addressed your comment...
If a public access point has a restrictive network policy, then QUIC will change nothing. There is nothing that QUIC enables that people browsing the web will demand. A user cannot even tell if they are using QUIC (or http2) for that matter.
The network operator is either non-technical and does not care about QUIC; or technical but trying to actively prevent people from using VPN and/or torrenting.
There are many ways to VPN that look like tcp http. tcp over tcp is okay if the connection is stable.
Typical coffe-shop APs have disabled UDP all together, mostly because it is not needed for HTTP and "intended use" of a WiFi provided at a coffee shop.
I would say they disable it deliberately to prevent VPN tunneling, its probably a sane decision to disable anything not needed for the intended purpose (or not putting effort in enabling it).
Actually my typical coffee shop does not constrain UDP in any way; otherwise DNS would break.
They are not sophisticated, they just do not want people leeching large amounts of data via the connection (which they basically perceive as http/1 or http/2).
I've been using ip over TCP for years when that was the only thing allowed.
For the most part it'll work no problem. Yeah tunnelling IP over UDP would be better, but ip over TCP is the only think you have... It's gonna work, as long as the underlying connection is stable enough.
If a public access point has a restrictive network policy, then QUIC will change nothing. There is nothing that QUIC enables that people browsing the web will demand. A user cannot even tell if they are using QUIC (or http2) for that matter.
The network operator is either non-technical and does not care about QUIC; or technical but trying to actively prevent people from using VPN and/or torrenting.
There are many ways to VPN that look like tcp http. tcp over tcp is okay if the connection is stable.