Because you long forgot how confusing it was, that you can't see if your keystrokes are accepted by the machine. This is a change for people, that are new to Linux/Unix
Worse than this issue, but kind of related, sometimes TTY1 (and maybe also the other TTYs) is being spammed by log info on boot, and if you have a TTY login it isn't obvious you can just log in anyway. Had a friend using Arch+i3 with TTY login, pretty new to GNU/Linux in general, so he kinda threw up his hands like "ah dang, can't log in, it's broken". I tried to tell him to just type his credentials anyway, but he didn't get what I was saying at first. Took a bit before we got him logged in and could address the other issues. I've had similar issues on my machines. I once had kernel log verbosity cranked up by accident, copied my config from another machine where I was chasing a GPU bug. Well, the same settings on the other machine were presenting way worse, constant never-ending line-spam, before and after login. Had to get into a graphical environment half-blind to see what I was doing and then turn down the verbosity. IMO there should be an easier way around that.
It's something that is confusing exactly once for a few seconds. It is at the bottom of the list of UX problems for either Linux or non-Linux systems.
Alternatively, if it's confusing, you shouldn't be doing whatever it is you're doing with sudo because you copy pasted a command from God knows where with zero understanding.