They said that roughly 95% of people who do trades have a mobile authenticator, so while I do feel bad for people who have circumstances out of their control preventing them from using it, I feel like that relatively small group of people shouldn't be holding security back for the rest of the Steam community
It's kind of the same principle of when people with an outdated game console want companies to keep making titles for it instead of moving on to the newer one
That's not to say that Steam shouldn't be working to get some sort of alternative or at least make sure it works on all smart phones, of course
and last but not least, not everyone wants to
I still don't understand why anyone wouldn't want to if they have the option
It increases account security to a level that makes it -- as far as I know -- impossible to hijack unless you're fooled into inputting your authentication code into a phishing website and the hijacker uses it
immediately before the code expires, or you store your backup codes in plain text on your computer and some sort of malware gets a hold of it
Losing your phone isn't a big deal because there are recovery options in place to unlink your phone and still log into your account to fix things
