Command center missions is the reason
Gold Missions, 2k per mission give or take at 200%.
If this is true your question is rather silly as you need for each spec-pet the weapon maxed therefor you want your followers maxed to give you the max ap return.
for the dk pets you need all 3(!) weapons maxed out. the 1k oh ressources to buy them should be the least problem
Maybe the OP missed that they reduced the cost of those from 10k resources to 1k. And even 10k resources is pretty meaningless.
Also - I, too, find it nice to max my order hall champions. Similar "sense of accomplishment" I have for improving my char really.
Would I rather play with the app/command table than playing the game with my character? No, of course not. But I like it when I take a short break from work to check my missions, it is not like I can do a dungeon or world quest then. That is what this "shity facebook" game is for. For you to be able to do something wow-related when you cannot play wow for real. And for that it is excellent.