Earlier quoted context omitted.
No, it cannot. It is well-thought.
There are 2^128 ipv6 addresses. If you store 1 bit (banned/unbanned) + a unix timestamp (ban expiration) for each of those IPs, that requires more storage space than exists many billion times over. To store such a block table you propose would require more memory for routers than any router has ever had and ever will have. An attacker could easily "flush" all entries in this table by, for example, banning a TB of ipv…
For example, if an attack is coming from a country you where you don't have many paying customers, but where there are many infected devices due to use of pirated outdated software, it is easier to ban the whole country than to figure out who is infected and who is not.