First off, it wasn't wrong. I'm not assuming people will make mistakes, I'm saying that people do not always do things that hurt their province just because it will help a couple others. Additionally, how long does it take a normal ghetto to kill a dragon? The lower top 100 and those off the charts can take 12-24 hours to kill one, even if the members are logging in. This is generally due to a couple of people not sending their share to kill the dragon. Factor in the change that would take place when some people are no longer affected, and I would bet money that a good chunk of kingdoms won't be killing their dragons any time soon, especially if half of the kingdom is unaffected.
Second off, to assume that just because something is good for one kingdom means it is good for the other kingdom is fairly stupid. Things are not always directly correlated. What is best for the kingdom depends on their strategy. There have been several times that we have sent dragons because that was best for our kingdom, and they have not killed the dragon because it was best for their kingdom to not waste troops. You have to factor things in like how pumped each kingdom is, the fact that one kingdom might have been saving OOW for a while and has the money for more dragons, etc. Just because it's best to send a dragon against a kingdom doesn't mean it's in their best interest to kill it. It's a lot easier to be OOW for a week with gold sitting around and drop a dragon than it is to have a dragon sprung on you out of the blue and sacrifice your units to kill it, when you're barely recovered from the last conflict. Additionally, if they have the gold to send a second one after you kill the first, and you can't take it away (Or won't, because your strategy involves actually hitting for acres or doing NS instead of RtV) then why destroy your army just to get a second dragon?
Third off, I find that training troops faster helps with being UB more than building buildings. Same with having half troop losses. If I don't start out UB (Which you would assume I didn't since we are talking about the speed it takes to get there) then losing half the troops as someone else means I can get trained back up a lot faster, and move past others in terms of trying to become UB.
Fourth off, they have always been more of a Dwarf personality, although you did used to see them on others when they had the half honor loss bonus. They are also an okay choice for some cows, although Merchant is generally a better choice.