We changed the question block system to a rolling rate limit that slows folks with a recent history of ill-received questions down considerably. There is still an outright block, but it takes a bit more in order to hit it, and it lasts (at the most) a year (or the amount of time it takes for your lowest-scored questions to fall out of the scope of a query).
Since it had been quite a while since your last question, and you still fall in the 'eligible to be rate-limited but not yet outright blocked' category, you were permitted to ask a question. But, be careful - if your next few questions don't fare well, the rolling limits will kick in heavily, but probably only once before you hit the longer-term block. Quite a few folks that were previously blocked now have one, or at most two more chances to try again and get it right after this change.
I can't go into too much more detail, but part of my goal was to give folks that probably could ask good questions if given another chance or two the opportunity, while folks that are never going to ask good questions still find themselves without the ability to do so for quite some time, after repeated attempts to show them where they're going wrong haven't worked. The beauty of rate limits in that regard is the pain of the bad questions is spread over weeks, which goes a long way toward keeping new questions that get visibility mostly interesting, while ensuring no one can say we didn't give them a fair chance.
Once we've got all of it firmly bolted down, no one can claim to be 'banned' from any of our sites, at least not in this respect. They might have dug themselves into an eleven-month time out, but they can't say they weren't warned. Meanwhile, we have been helping folks that just got off to a bad start without the benefit of the rate limits who are still in a long-term block get back into better standing for another (limited) chance.