Diablo 4 doesn't have WASD support on launch. The developers of the Diablo 4 wanted to give gamers the option to play with a controller even on PC, but it seems the decision caused significant changes for those who're more used to the traditional controls.
Previously, the creators of Diablo 4 talked about their absolute confidence in the product before launch. According to art director John Mueller, and associate game director, Joe Piepiora, they learned a lot during the last server stress test, and they've corrected small issues in the background as well that likely would've caused problems for players. Based on their comments, it sounded like they have painstakingly gone through every little detail to make sure the launch of Diablo 4 is a success. However, it seems WASD support was completely omitted. It's worth mentioning that Diablo 3 had no WASD support either, but Diablo Immortal does have it.
There have been various sources that have confirmed the lack of WASD support for Diablo 4. Rod Ferguson, the executive producer of the Diablo franchise, has also confirmed this recently to a player. According to him, they're "very aware" of the feedback, but in the meantime, he's recommending to most with accessibility issues to give controller support a try. The lack of WASD support started a passionate discussion within the gaming community. There are those who feel strongly about a need for WASD support due to accessibility reasons, as mouse control can be either painful or just entirely impossible with certain conditions. A controller can help, but it still requires the type of movements some may find difficult. There are also those players who simply swear by WASD control, finding it the easiest way to navigate in an RPG.
Of course, there are plenty of gamers who are big proponents of controller support and wouldn't play the Diablo games any other way. There are even those who play with just a mouse and find the experience enjoyable, but there are a lot of fans who simply find the omission of WASD support a puzzling choice. However, based on Rod Ferguson's reply, it seems safe to assume Blizzard plans to introduce WASD support later on, otherwise he wouldn't have used the words "in the meantime" when recommending controller support.
Considering there have been quite a few gamers who complained to Blizzard about the lack of keyboard controls, the company will likely do its best to fix the issue as soon as possible. Until that solution arrives, hopefully, most will be able to enjoy Diablo 4 with a controller as well.
Diablo 4 releases June 6 on PC, PS4, PS5, Xbox One, and Xbox Series X/S.