There's a significant portion of the playerbase (not me) that's allergic to any movement techniques related to jumping and sliding. From what I can tell, the reason why these players don't want this, is often related to the perception of what people want Battlefield to be, rather than what Battlefield has historically been.
They want Battlefield to be "grounded". They feel strongly about seeing people slide or jump, because that brings up their negative associations with Call of Duty. This isn't necessarily based on any detailed understanding of the game mechanics. Instead it seems to be more of a matter of authenticity and immersion. I get the impression that many people view Battlefield as more than just a game, they put heavy emphasis on the overall experience as well. They want to feel that they are playing a realistic shooter, even if it isn't realistic. So any game mechanics that fall outside of those somewhat subjective boundaries are frowned upon.
In my opinion, the most substantial problem here is that it's quite hard to quantify feelings and many players don't even know what they want. There are many times where the Battlefield community asks for things, that when implemented indirectly lead to dissatisfaction from the same people that asked for those changes.
For example, they complain the game is too fast and that they want to nerf the movement, but once the movement is nerfed they find themselves struggling even more to keep up with the pace of the game, as the pace of the game isn't defined by movement alone.
Unfortunately, Battlefield Studios seems to want to cater to these players. It's essentially a repeat of Battlefield 1, where they kept listening to the Reddit crowd and they ended up nerfing the movement and the slide to the point where it became entirely pointless to use. I really hope Battlefield Studios doesn't cave too easily to future attempts to nerf the game.
Jumping with knife out makes you nearly stop mid-air.
This is confirmed that it will be fixed.