"Those same people saying it's bad are the same people who break rush line rules, don't turn off their phones during a performance, arrive late to the performance or late after intermission disturbing the people around them, singing badly during the performance, wooing during the performance, eating or chomping during the performance and talking during the performance. It's amazing that there are people out there who do at least one of the above consistently, but then choose to call out someone who is stagedooring a show they didn't see."
I too, am guilty of none of those things you mentioned. Not sure how you made that leap. In fact it's quite the opposite. The people doing all those things you mentioned are usually the same people who go stage-door shows they haven't seen.
"Just because you get his autograph doesn't mean people who saw the show won't."
That's probably true in this case, but in many cases, there are so many autograph-hounds and other such people clogging up stage-door barricades, that many of the people who saw the show don't get to meet the actors. I've seen it. I've been one of those people on several occasions.
"If you walk through the theater district, and pass a theater where a big star is appealing, you will see s lot of people lined up behind the barricades while the show is still in progress."
Yes, many people wait outside shows they haven't seen. Just like many people take out their phone during shows. Just because many people do it, doesn't make it good.
"Secutity is there and know these people didn't see the.show, but security doesn't say anything. Why? Because they don't care."
Security doesn't case because it's not their job to care. They have other things to worry about.
"As far as etiquette goes that sounds a little crazy to me. You're not at a black tie event or even inside the theater. You're asking for someone's autograph."
Black-tie events are not the only situations that have a set of etiquette rules. That's ludicrous. Asking for autographs has many different rules of etiquette. So does pretty much every social situation ever - it's just that the rules change and have varying degrees for formality.
"Saying you can't ask someone for their autograph unless you saw the show means, in effect, that you have to pay for it which is ridiculous. Is it rude for people with comp tickets to ask for an autograph? They didn't technically do anything to support the show other than help fill a house."
It's not a question of money. It's a question of time and respect. It's respectful to have seen the show in question before going to the stage-door to meet the actors.
"I bet some of the people who will tell you it's a bad thing to ask him for his autograph without having seen the show, which he gives out free to you and them, would have no problem second acting a show where they are getting something for free that others have paid for. "
You bet wrong. Well...maybe some people. I can't speak for everybody, but I have never done that, nor would I.
And look, I'm not saying the OP is a bad person if they decide to go ahead and stage-door the show, but they should be aware that it is considered a breach of etiquette. I get it: sometimes you breach etiquette when you're desperate and circumstances lead to it. I've done it in other areas of my life from time to time. But I'm aware that I'm breaching etiquette and try not to do it frequently. The OP even said that it seemed rude to do it. It's not life or death, it's not like the OP will get arrested. It's just more respectful to have seen the show first.