Is it just me that thinks Purim Torah detracts from the whole idea of Mi Yodeya? I understand the idea that it's Adar and why not, but I feel it detracts from the whole website (especially for newcomers looking for real Q&A). Why can't the Purim Torah be in a chat or some area separate from regular questions?
On the other hand, Purim Torah brings readers to Mi Yodeya who wouldn't otherwise visit, potentially exposing them to valuable (seriously, from the point of view of MY's general mission of spreading knowledge about Judaism) content. Every Purim Torah page has links to the front page, to seasonal tags highlighted in Community Events, and to serious questions that the algorithm lists as "Related." In addition, the better Purim Torah posts allude to and ideally link to real information about Judaism, thus teaching through humor. So, there are ways in which Purim Torah season helps with what MY is generally for.
In addition, of course, it's fun.
So, we have qualitative values one way, and qualitative values the other way. In my opinion, doing Purim Torah in the time-limited and strictly labeled way we do is, on balance, worthwhile.
Beyond qualitative arguments and personal opinions, it would be valuable to try to bring some data to bear. How many newcomers get confused? How many readers look at Purim Torah, and nothing else? How many look at Purim Torah and then at other content? What is the effect of Purim Torah season on non-Purim Torah content productivity? Answering questions like these with numbers could make it much easier to engage in informed deliberations about policy.
Personally, I just have a few tags which I block. One of them is the [purim-torah-in-jest] tag.
So unless the question makes it onto HNQ, I won't even see that there is such a thing as Purim Torah (unless I specifically look for it).
To block a tag, see https://judaism.stackexchange.com/users/preferences