After skimming through some popular threads about mihoyo's response to leaks, I get the feeling that people don't really know what they're angry about because it just derails into discussion about problems with the current state of the game, which I don't think has much to do with the leak issue. It seems like misplaced anger. I want to try to provide some context for why mihoyo might have responded the way we did, and what we can understand about it instead of grabbing pitchforks reflexively. Because this is an issue that almost all game companies face, not just mihoyo.
1. They literally have teams dedicated to creating teasers, trailers, and other media to generate hype about new content. They plan when to release more information about upcoming content, probably when players are in a downtime when they have experienced most of the content currently available. Just a reasonable tactic to keep players interested in an evenly spaced out timeline, instead of leaking stuff at the beginning of 1.4 so that everyone is distracted before even scratching the surface of 1.4. Already people are complaining about how "underwhelming" 1.4 is compared to 1.5 and just like, wat. I guess they're from the future.
2. They work in 6-week cycles where new content is rolled out. What this means is that they will be working on various content simultaneously, some that take a lot longer than others. Which is why you won't have an equal amount of new and exciting content every patch, some will be filler while they focus on bigger content in an upcoming patch. Knowing this, it's easy to become distracted and be less appreciative of the current patch because you found out about the next patch so soon. And it might kill your interest in the current patch a little bit. Give developers the time they need to uphold the quality they strive for. Also, when something you've been working so long on get leaked in a premature and less polished form... well that just feels really bad for the people who worked hard on it.
3. People become angry about leaked changes, even though it wouldn't have hurt them if they just didn't know about it. Let's look back to the Zhong Li release, where people complained about the bait-and-switch of Zhong Li being nerfed as a DPS. Because his gameplay in beta was leaked. Beta is where you test and change things. Not very reasonable to call this a bait-and-switch, but this will happen yet again because there will inevitably be changes leaked during beta and people won't like it.
4. It's a free game! They need to keep player interest and sales from dipping patch to patch to keep investors interested! I understand that people want to know ahead of time whether or not they should save their gems for the current patch or for the next patch. Well here's the thing, banners last for 3 weeks (with the exception of last patch) so you just need to be patient. But if players were to suddenly lose interest in the current patch's banner because the next patch's banner got leaked on day one, oh no, all that planning went to waste.
Anyway people seem to be glued to the idea that leakers act more in the interest of players and mihoyo is just greed. Ehhhhhh. They're both greedy with their own motives, let's be real. The difference is that one of them uses that greed and puts in hard work to provide more entertainment for all of us.