[amanda99]

Two things:

1. "Password" is a magic word that makes people less likely to just paste it into anything.

2. Username + passwords are two separate pieces of information that are not normally copy-pasted at the same time or have a canonical way of being stored next to each other.

[victorbjorklund]

1) Make sense. 2) Not sure about that. If someone shares their password with someone else they probably share both the username/email and the password

[amanda99]

Yes, people share usernames and passwords, but there's no single canonical string, like "username=amanda99&password=hithere". For example most of the time when I share user/pass combos, they are in separate messages on Signal. You type them into two different boxes, so you normally copy the username, then the password in separate actions.

[nightpool]

I mean, for HTTP Basic there literally is a single canonical string, and it's not uncommon to see people send you links like https://user:[e-mail].

I think the arguments other commenters have made about logging, browser history storage, etc are more convincing