not just any random person can submit a .deb and have it go live on the gpg-key authenticated debian mirrors.
https://wiki.debian.org/Packaging
https://www.debian.org/doc/manuals/debmake-doc/index.en.html
curl into bash can be as quick as "ooh look shiny new thing on website, let's copy/paste this string of text into my shell"
Actually, it should probably get even more hostile a reaction, since installing it that way usually means you won't get any updates for it. If you absolutely must install software from a (trusted) source other than your distribution, adding a source and then using `apt` is the way to go.
And each 'curl https://' packager has its own idea where his software should be installed. And many of them are not even providing automated way to delete their application.