A bit late but I feel as though I still have a bit to add, so here it goes...
I watched Pat's video shortly after it was released (pretty sure I saw it before PDP released his video) and the only reason I know it got negative feedback, other than this thread, was Reviewtech making a video about it. Shame, I thought Rich was a Pat watcher too, after that, but I guess not. Anyways, my initial reaction to the podcast is that Pat and Ian were both very wrong, especially Ian.
For one thing, Blizzcon is itself a product, people are paying money to be there (and aside from the ticket price are also sacrificing vacation days, travel expenses, etc.) and using the capstone of the week to announce something that these people actively dislike... what did they think would happen? Perhaps not the open mockery but audience boos should have been a given. The April Fools comment, in particular is a reference to Blizzard's yearly April Fools posts, which are a real life thing and, 8 short years ago, actually included trashy looking fake mobile games. It was a Blizzard reference from a Blizzard fan. A super fan, someone who dropped a load of money to come to a week long celebration of Blizzard and their good but very over-rated games. A potential whale. Ian wanting this guy thrown out of the show is stupid, from a business perspective. And of course the presenters (who have little responsibility for the game being greenlit, etc.) had a tough job to do and will hopefully be forgiven for any on-stage snippiness with their fan interaction, but they are ultimately on the clock, they are being paid for this, probably more money than a lot of the Blizzcon attendees make.
A big error from Pat was that he said gamers would get their real Diablo game, regardless of how this turns out. Probably true, but ask the people still waiting for Warcraft 4 whether it actually is. Because its pretty obvious that WoW's success killed the RTS aspect of that franchise. The simple fact is that if this Diablo game is a huge hit, it will have an impact on the main series, probably a negative one. People in this thread have mentioned Pat being unaware of current game trends, I would say that this is a pretty big example of that.
Gamers, like all people who buy products, are not entitled to anything other than what they buy actually doing what it says it will do on the box. Sometimes they don't even get that but in this case I suspect that they will. And yet, they do not have to buy the products on offer either. In this case I hope that they don't. Jim Sterling, in his most recent video, flipped the question on its head. Are these companies not acting entitled too? They give us less choice and variety each year while systemically designing their products to ask for more money, even after they've been paid for. They try to switch to a model where the consumer no longer actually owns what they buy, just a digital license to a digital product that might not work in two years. Why does Blizzard think that it is entitled to sales of a game that already exists, just with Diablo art pasted over it? Why do they think they are entitled to money for "purple coins" or whatever their secondary currency for this game is going to be? Does it cost them more money to produce? I doubt it. They are certainly within their rights to do any of that stuff, but if they do I hope their fans look elsewhere for entertainment.
And, finally, to take it back home to the topic of Pat... I do not like Ian. He whines a lot and I feel that his histrionics take away from the podcast. I dislike hearing him bring his personal politics into retro gaming topics where they are totally irrelevant too, though those moments typically do not make it onto the Youtube clips. As a retro store owner he has a lot to add to the discussions, but his personality sucks and I suspect that his store is one of the ones that has really good inventory because they over-price stuff (you all know the type of place I am talking about.) Most of this discussion was his fault, Pat was just along for the ride.
edit: And there Ian goes again, in the latest video, saying that Microsoft still has some sort of ownership stake in DKC. They do not. They have never. It has always been available for Nintendo to use assets from, and Nintendo has always used assets from it. Ridiculous.