Remember that youtube channel Odyssey games? Remember all the fun pvp gamemodes they showcased on their servers? Im sorry, but there is just more to terraria than just collecting stuff and digging holes in your singleplayer world. PvP has always been a big part of this game for me and my friends. One PvP focused server I played on back in 2013 would get 50+ people per hour. Some of the most dedicated terrarians I know are long time pvpers, and 1.3 was just a big middle finger to their favourite part of the game. Like @Fearolife mentioned, there are still servers centered around pvp out there (Quite a few, actually. PvP has always been a big plus for servers), one community has actually been experimenting with an early game class based CTF sub-server(similar to tf2 but with terraria building elements) last year and it has gained quite the following on their forums.
However, I believe late game pvp is where its at, and im really dissapointed 1.3 didn't cater to the "PvPers" as 1.2 did.