I don't know that we need more Ion Hazzikostas in the game. It seems to me we have quite enough already. I do think that the design team could stand to have a couple of people on it that better understand the casual player mindset and what they want. They missed this entirely in Warlords, over-compensated in Legion (but too much is better than not enough) and played it safe in BfA. I think there's a lot about BfA that could be better but for them Legion was a pretty great success (especially after Warlords) so "more Legion" probably seemed like a reasonable thing.
The problem with that is the length of time that each expansion takes before the next one. I liked Legion as much as anyone but after that I was ready for something that moved on a little more. Admittedly, it's pretty hard though to think up brand new concepts for a game that's been around as long as this one. Blizzard is great at taking someone else's ideas and polishing them up nice but it's been a while since a major MMORPG came along to borrow from.
They aren't going to repeat what happened in Warlords though when players who played very casually and not every day still ran out of things to do. That's a primary driver behind where we are now. Contrary to many here I don't think Activision is the problem. I think the reaction to Warlords and people running out of things to do was as traumatic for the design team as Cataclysm was.