It's a no-brainer.
Can you give me an example where production quotas have led to more efficient production of a good than the free market method?
The quota is a given due to hardware and software limitations. It's not like right now you can remove the 1mb limit and you'll be successfully mining 20-100-1000mb blocks. It can't happen. That's the reality of it. So you make the best use of what you have. That's how all technologies evolve.
In the 90's, when email started getting traction, as soon as people had a few kb / a few mb mailboxes, mailbombing begun as an attack vector. You could literally clog one's email address, making it unable to receive any email because you simply carbon copied the same email 100 or 1000 times, or put a small attachment and sent it 10 times. If people were as "bitchy" back then, they would be saying "oh what's this crap with this email thing, this can never work, it's DOA, it can't scale" etc etc.
As such attack vectors became apparent, successful mailbox providers realized the folly of allowing "a few kb / a few mb mailboxes," and limited mailbox size to a few hundred bites.
...of course, literally *no one* ever did that. Email account caps grew and grew. That's why we killed email in the cradle, by forgetting to limit mailbox size & devising crazy spam filters instead.