[0x457]

I understand that, but what I'm replying to says: "TBH ISPs that hand out /64's shouldn't be allowed to say that they support IPv6 because it's a completely non-standard — not as in "uncommon", but as in "violates the documented standards" - setup."

[hylaride]

RFC6177 specifically recommends a /48 to /56 because future security measures may require subnetting, even on home networks (eg having IoT devices on a secure DMZ).

Basically, giving out a /64 is the modern equivalent to ISPs saying "you have to pay extra to have more computers on the internet and you're not allowed to use NAT" that was actually a thing up until the mid 2000s.

The frustrating this is that there's no reason to do a /64 as IPv6 was literally designed to hand out huge IP ranges.

[0x457]

Well, per RFC2119:

SHOULD This word, or the adjective "RECOMMENDED", mean that there may exist valid reasons in particular circumstances to ignore a particular item, but the full implications must be understood and carefully weighed before choosing a different course.

Not following recommendation from RFC6177 by allocating a perfectly valid /64 (it being inconvenient to some is another story) is not "violates the documented standards"