nobody wants to have to hard fork every year
That's stupid, because that's not what the guy was suggesting. His idea can be implemented in a single hard-fork implementing a *rule* not yet another hardcoded magic number.
Exactly.
I just think that rule should be very well thought. If it is not done right just doubling the block size limit once the current limit is approached is just like not having a block size limit at all. Some spam-prevention mechanism should be in place to avoid blocks growing non-stop because of some sort of spam attack.
Maybe it would be enough to have a rule that says that the block size limit should be approached for long enough to make such an attack economically unfeasible.