... like that one crazy uncle who won't stop with the conspiracy theories, you mean?
Delta is a pretty good airline that has done a great job of merging with Northwest and largely creating an end result that is better than the sum of the parts. That said, they've screwed up a few key areas - information technology integration is the main one amost of us would come to consensus on that needs little explanation.
Perhaps more relevantly, Delta's also not particularly good at communicating program changes. Some examples that come to mind are the loss of existing year choice benefits for newly qualifying PM/DMs, the Zone 1/Premium boarding mess during the SkyPriority rollout, E fare mileage earning, the "Have One On Us" coupon glitch, the preferred seating changes that briefly broke exit row selection, and the ongoing controversy over the award calendar. In each case, Delta eventually seems to end up doing the right thing - but it takes 50 posts of FlyerTalk forum drama before the issue gets attention from the right people to address the issue. The eventual response is greatly appreciated, but the process is much messier than it needs to be and I think it tends to unnecessarily foster a bit of overall distrust from the forum regulars.
That sort of thing unfortunately generates enough noise on this board to drown out discussion of the remainder of their operations (irops handling, front line customer service, domestic upgrades for elites, etc.) which by and large run very smoothly in my experience. I think as Delta irons out these issues over time, you'll hopefully see the tone of the FlyerTalk forum correspondingly become more positive.
In the interim, this post is a good wakeup call for us all to tone down the rhetoric a bit. Delta isn't a total disaster, and wild rants about the company aren't helpful, productive, or frankly credible as long as you're still choosing to fly with them. They do have some lingering and systemic issues, though, and continued constructive highlighting of them on FlyerTalk is totally still fair game (AvidFlyer's well-researched thread on E fares is a gold standard for how this should work IMHO.)