Obsidian made this decision while being fully aware of the existence of Broken Steel, and of the reactions to it.
They made the decision knowing what they were doing. A "play after the end" option isn't needed because they warn you right before the end.
Giving you the option to play on with a "no changes will be reflected" note like in Fallout 2 would be silly. Completely unnecessary.
Honestly, all you miss out on is one end game quest and a bunch of people saying "hey, there's the hero". Anything more would require massive changes to the end of the game.
This is your justification? They told you so... so that makes them right?
One of the first mods I downloaded for New Vegas -did away- with the finality of Obsidian's ending. Do you know how much time that took me? Almost none. Do you know how much work they put into it? A couple of edited scripts. Someone came along and actually made an even better version of that mod, which causes the world to slightly reflect the changes your ending made... and these aren't even PROFESSIONAL game designers here. These are part-time modders!
The excuse is old... and tired. Game designers are not gods among men, and they sure as hell aren't the only ones who get to dictate what is right and wrong.
If there is even a SMALL group of people who disagree... who
revile an aspect of your game... then there is a cause for concern. That's when you ask yourself... is it something I did? Is there something I could have done differently to make this better? What can we do differently next time?
Bethesda already had that issue. Broken Steel. That was their result... and it was fairly middle-of-the-road.
Obsidian went the complete other direction, ignored the fact that there were people who STILL wanted to play on beyond the 'end' of the game, and in fact it would have taken them all the time and effort of a decent MODDER to make it possible. A modder did it... and did it well. I'm lucky I bought it for the PC... because hell... who knows if they'll ever come down off their high-horses and say,
'Sure, people who want this game to go on forever even though we think the artistic vision of our story is more important... we'll take four minutes out of our day to change a couple scripts.'
... much less actually make a full-out expansion with year-long production times and full-game quality resources and whatnot like I would -really- love to see. Their story is good. It warrants saying that I -liked- it. I liked the ending scenes. What I didn't like was the ENDING.
Saying: "Here... this is the end for you... go any further, and you can't play anymore." is completely immersion-breaking for me. My character just worked up to this moment. My character just prepared for the greatest victory in his/her life.
"Congratulations, sir... we've got them on the ropes now. This is it. The final battle. If we take them down here... we can push them clear on out of Nevada. There's only one problem. If you go on ahead, there's no turning back. And if you win, that's it... game over, man. Don't worry though, the battle won't ever start without you... so we can just keep this waiting for days, or months, or hell... even years. Why don't you just go on back home and take a nap first? This isn't anything important."
That's the kind of logic that gets used at the 'end' of New Vegas... and I hate it. It drives me crazy. It kills any semblance of realism the game had by presenting exactly the same kind of moment that Fallout 3 did... the point of no return before a massive battle you've been building up to for most of the game. I -want- to have my victory. I want to win... and then go home and relax, eat some Fancy Lad's Snack Cakes, and watch some of Razorwire's fine TV.
I'm not alone... and there's enough of us that feel this way, that the topic comes up again and again and again...
Forgive me if I'm not really impressed by: "They saw the mistakes of their predecessors and made the same choice anyways..."
They did a much better job of it. They probably ended the game as best as it could ever have been ended. But it was a mistake to not include four lines of code which could have saved a lot of people a lot of grumbling.