It's interesting that you should put it quite like that. I sometimes wonder why I've maintained my membership here, let alone my subscription. DA has some very good aspects. It also has some that are frustrating and disappointing. Like yourself, it is the relationships, primarily, that keeps me coming back. As in "real" life, mine here are quite selective, and also extremely valuable to me. In making and keeping friends, I have always preferred quality over quantity.
I've come to accept the fact that DA is more of an oversize fan gathering than it is a regimented commercial site. Having grown as large as ti has, it has provided the owners with commercial opportunities I get the sense they did not foresee when they first designed the site. That doesn't change, however, the way it functions, or what it is, at it's core. DA is an extremely informal construct. If you review any of the pages that are created form time to time to celebrate or report on the progress of development, or community get togethers sponsored by the site owners, the sense that this is a site made by fans for fans is re-enforced. This accounts, I believe, for the informal (even dysfunctional, some would say) way many aspects of the site function, despite it having grown as large as it has. In much the same way that less developed fan organized sites primarily focus on just those elements of their object/subject of adoration which most appeal to the developer (s), everything about DA that isn't directly related to the interests of the developers seems to function either poorly, or not at all.
Having reached these conclusions, I have come it find it far easier to accept the site's short comings. I've also come to access it less as time has gone by. I still come to the site nearly every day, but I now only stay here long enough to do the few things I still use the site for, such as staying in contact with friends and viewing their new work, and then I leave. I also suspect that the longer one is a member here, the more this becomes true for anyone who is not specifically attuned to the core reasons the site was created for in the first place. DA can be used for other purposes, I know, such as getting your work in front of a large audience which is generally predisposed to be receptive to it, but I still feel that users with generalized requirements from an art warehouse and/or promotional site will come to use DA in ways not foreseen by the authors, nor having anything to do with the actual design or purpose of the site.
All in all, however, I am grateful DA is here. Despite it's less appealing aspects, it is just about the only place on the web where I could have met and forged or reforged friendships with all of the people I maintain associations with here. Between more recent contacts, such as yourself, and the rekindling of friendships with people I have known for decades, but lost contact with through the years, DA has come to mean a very great deal to me, if not for any reason I believe the authors might have suspected when they developed the site.