I get you - but how many places do you not get sms reception but you still have enough internet connection to be trying to log in to LinkedIn? (Inside a data center, maybe?)
"The lobby group for Australian telcos has declared that SMS technology should no longer be considered a safe means of verifying the identity of an individual during a banking transaction."
and
"SMS is not designed to be a secure communications channel and should not be used by banks for electronic funds transfer authentication,"
Plenty of places around London where I have WIFI access but no 3G/4G signal (tube stations, various Starbucks, couple of Costas, my flat, DB's Bishopgate office in 2014, etc.)
It makes e.g. Twitter's insistence on SMS 2FA annoying (since their "we've sent you login request to your app" just doesn't work for me, I'm stuck with SMS).
