You must really look down on classical musicians who sit there in the orchestra with all that sheet music right in front of them...out in the open....
My feeling about lyrics and teleprompters is that if I wanted karaoke, I'd go someplace cheaper. For $50-100 bucks or more of my money for a ticket, I think that the least that the performer should do is show up on time and remember the lyrics. And, as far as orchestral musicians are concerned, I need to say that belting out three stanzas and the chorus of "Runnin' with the Devil" is quite a bit different than playing Beethoven's 5th from memory.
Don't get me started on pop tarts (Britney Spears, etc) that lip-synch.
Finally, I had the pleasure of catching the Stones (fantastic Arena show, BTW) a few years ago. Not a teleprompter in sight....no way there were any around because for a significant part of the show, there wasn't a place for them in the set design. So, unless Mick had the lyrics written on the back of his hand....