I'll reconstruct it the way I understood it.
1) Velhart made a post mentioning that people wanted to see more unique stuff for the relic.
2) I responded to say that I was afraid we'd have to give up content for that because of development constraints.
3) From this point, I'm actually not entirely sure what Velhart was getting at—he seemed to be saying that I was trying to excuse poor content quality (like Diadem), which I wasn't—I've talked in numerous places about how I felt Diadem was a big disappointment.
4) That ultimately wasn't what I was talking about though—the quality of the new content doesn't have much to do with whether or not they have the resources to create other new content, which is why I reiterated my original statement about development concerns probably being part of the reason we don't get new content for the Relic.
5) Velhart's next post goes on to say (I think) that the development team should be doing less than they currently are because of the drop in content quality, which is honestly something I could get behind—I think quality is better than quantity, for sure.
6) But at this point, we still weren't talking about what I was talking about, which was that they can't add new stuff to the Relic quest without most likely cutting out other things—so I just gave up and admitted I wasn't sure what he was trying to discuss with me at that point, as he seemed to take my train of thought and go off to talk about something different. It didn't help that he went from asking for more content (for Relic) to seemingly saying they should be designing less (which is closer to agreeing with my thoughts on the matter than not, since it speaks to the the problem of the developers perhaps having too much on their plate).
On the subject Velhart was seemed to be talking about that I wasn't talking about, I actually haven't really noticed a significant drop off in content quality for most stuff in Heavensward so far. I think class balance has largely been worse, but the dungeon quality is roughly the same (and in my view, somewhat improved). Diadem is a mess, but so were Hunts, so it's not necessarily indicative of a drop in quality when they were already releasing content that was a mess due to bad assumptions regarding player behavior.
About the only place I see a significant drop off in content quality is with regard to Alexander versus Binding Coil of Bahamut, with the latter feeling a lot more haphazard in design in a number of ways, both in regard to the battle content as well as balancing and story construction.