Why are snowballs not knocking back LAN players in Minecraft 1.13.2

In one of my worlds, I simply want to have a snowball fight with players that are connected through LAN. The connection is perfect on both computers and there is no lag. PvP works (fist hitting) so there is no scoreboard prohibiting friendly fire. However, for some reason eggs and snowballs have no effects on players. They hit the players (you can see particles) but no knockback occurs. Is there an enable/disable command that came out in 1.13 that I am unaware of, or did the developers take this away? Any insight would be great.

This is due to MC-3179, which was closed as "works as intended" by Adrian Östergård on 2016-08-23 (when 1.10.2 was new) without an explanation.

To clear a few additional things up:

• Snowballs never dealt knockback to players. Bukkit servers had or have this feature, but never regular Vanilla servers. In this comment someone tested a lot of versions, from the version in which snowballs were added up to 1.8.3.
• "What would be the point of snowballs if they had no knowback effects on players?" Snowball fights can also be fun without knockback. Just a few months ago, I threw a lot of snowballs at someone while he was streaming. It would have distracted a lot more than being funny if it knocked him around all the time. If you want to move someone around, a fishing rod can be fun as well, or a bow enchanted only with punch 2, nothing else. Snowballs can also be used to intentionally anger mobs, which is for example often used in pigman farm.