Ahhh, the bliss of having the Snail's posts invisible. Regardless of what was going on above I was interested by the title, although a question that has been asked many times over the years. I pulled up the last year's worth of registrations/day and new posts/day which should be attached to this post.
Clearly this is mainly quantitative, although does reflect quality to some extent as those stats would quickly decrease if every one of the new posts was very poor. I'm sure there are loads of odd influences tucked away in there - perhaps 3RTR were discussing a particularly hot topic that day, or the word association game was popular or the Chinese spammers were on a roll.
Overall conclusion though: No, although clearly an upwards trend would be preferable to the basically flat graphs.