There definitely is an element of people just not liking it because it’s new, but there’s also an element of not getting any say in it whatsoever.
Also, they really do get in the way. They make it harder to get a good seal between your mouth and the bottle at any angle, and at the top they hit your nose. They are slightly harder to use, especially if you’re using one hand for any reason, including if you only have one hand. Removing them without tools results in a sharp bit of plastic which pokes and irritates your skin.
Finally, this is another patronising effort which makes consumers lives more difficult (by whatever amount) while not doing enough to combat plastic waste.