I don't agree with that
as it would mean I should also be against saying 'cheers' to mean goodbye

also, and I might be wildly off the mark, but I'm pretty sure hello or a variation thereof was used to hail someone or get there attention in much the same way as hey
( Vipros. clever got me this far, then tricky got me in, Wed 26 Aug 2009, 12:09, 2 replies, latest was 16 years ago)

Wikipedia to the rescue
According to the Oxford English Dictionary, hello is an alteration of hallo, hollo, which came from Old High German "halâ, holâ, emphatic imper[ative] of halôn, holôn to fetch, used esp[ecially] in hailing a ferryman." It also connects the development of hello to the influence of an earlier form, holla, whose origin is in the French holà (roughly, 'whoa there!', from French là 'there').
( The Light in Chains don't touch the Pope's boner, Wed 26 Aug 2009, 12:15, Reply)

I'm certain that's right
But I don't like this change. This language change in particular gets my goat.

There's still an element of rudeness to hey. Would you use it to meet potential in-laws for the first time? At a job interview?

So why use it to otehrs? It's not like there aren't any other options - Alright? Wotcha? How-do? Hi?
(Land of Green Ginger It's dreamy weather, Wed 26 Aug 2009, 12:26, Reply)

there's nothing wrong with informal greetings used in the correct context
I like to be rude to my friends, so a greeting that is rude is perfectly acceptable to me.

frequently I will answer the phone with the word "cunt" if I know who is calling.
( Vipros. clever got me this far, then tricky got me in, Wed 26 Aug 2009, 13:19, Reply)