I really don't think the site is like this because they lack capacity. It's pretty clearly an intentional design choice in my view, like with Craigslist.

But no, I do not have any information on their staffing situation. I presume you don't either though, do you?

Indeed I don't. However it we examine the pace of new features of the last several years (I can't think of a single way this site has changed over that time period), it's reasonable to surmise that there isn't a lot of development of the user accessible/visible portions of the site, and that leads me to guess that they don't have much in the way of dev. resources.