TSR made some pretty boneheaded moves as well. Its not like any company is immune from making mistakes given hindsight is 20/20.
True, but at the end of the day, they were in the business of making D&D and related games. So if they did poorly they were incentivized to do better.
However, WotC's primary purpose is selling Magic cards. That's their business and they can be excellent at that and it doesn't transfer to being good at D&D as the product lines are so very different. And there's very little incentive to be better as the money D&D brings in is pretty much insignificant. The money D&D makes in its best year is a tenth what Magic brings in during a slow quarter. There's no reason to bother working hard to learn the business of D&D, because every hour spent making an extra dollar could be spent making ten times as much via MtG.
MtG is apparently doing very, very well. It's a good time to be a MtG player, and most gaming stores I know rely on that card game money. But that doesn't transfer to knowing how to publish a Tabletop RPG any more than that skill would transfer to publishing a board game or a mobile app.
I have some faith that there's some kind of business plan for D&D, and a good portion of that business plan is honestly not in the actual game production. Think of the Disney model, sure Aladdin was a great movie but the money is in sell Princess Jasmine bed sheets and t-shirts to little girls. Its the reason that Disney bought Marvel, Disney exces don't gives a rat's ass about comic book sales compared how much money Avengers makes at the boxoffice or how many Spider-Man underoos get sold.
Disney/Marvel is pretty much a good comparison. You think any Disney executives care at all about what makes a good comic book? About keeping the comic book fans happy?
That business is peanuts. It's insignificant. It's an audience of 250,000 people that makes a few dozen million each year, compared to the billion dollar franchises. The comic companies can run around doing their own thing and so long as they don't lose money no one really cares. Most Disney, even the ones that have dealings with Marvel, very likely have few ideas of the nuances of actually publishing a comic or what makes a good comic versus a bad one. (And given the state of the comic industry, this kinda shows.) And Marvel only has one business (selling comics) compared to WotC's multiple divisions. It'd be like if 95% of Marvel was dedicated to comics and 5% was dedicated to, oh, postcards. Even if there were people who were really invested in learning the business of comic books, they might not extend their knowledge base to the secondary department of postcards.
Hasbro execs wants D&D to do that for them, and they believe that WotC is the team that is going to make it happen. PDF sales are honestly a drop in the bucket, and I don't think they actually care that much about them in the big picture.
PDF sales make be a "drop in the bucket" but they're still a source of revenue. D&D needs all the money it can get. And they're useful for the players, which keeps the fans happy.
I'm always using my Pathfinder PDFs. Continually. I'm reading APs at work during my break, or preparing for an adventure, or writing some homebrew content. Even if I don't have my iPad, I have them on Dropbox so any PC becomes my gaming library.
And I'd probably do that with 5e as well. I'm doing a 5e Ravenloft update, so it'd be handy to reference the books anywhere, so I can do a few minutes or race design or subclass balancing whenever I have some free time, not just at home with my books beside me. Being able to ctrl-F to search for a phrasing, or the frequency of a saving throw, or counting how many monsters have a fear effect, etc.
Really, the only thing Hasbro executives care about D&D is the IP it brings to the table. Again, like Disney, which doesn't care about comics but wants the characters. They don't even really need the TTRPG any more than they need the mini game or the character builder program. That could be licenced just as easily. If WotC thinks it can save money by doing the RPG out-of-house it will layoff all of the remaining half-dozen D&D brand team and keep the licensing people on staff to manage that.