I think you're vastly overstating the importance of the userbase, and as I said before; having the original available for purchase will have a negligible impact on the amount of players playing the Remaster, if any at all. I'm confused why this is even in dispute. They're not removing the original out of courtesy for the fans.
Only reason it could have an impact, would probably be due to the Remaster being subpar. And again, if that were the case, I don't see how it's better for everybody to remove the good version and replace it with the inferior one; leaving people with no choice. The "userbase" won't be better for it.
The idea that they would remove the old version because the remaster is worse is laughable. Furthermore, it quite clearly is not.
And I don't know why you continue act both like having the original is very important, but also not important to the playerbase. Choose. If it is important, then it needs to be more important than the impact it will have on the playerbase. If it is not important, then there is no need to keep it around.
To me, the online portion of Dark Souls is a major part of what makes it unique, and all incentive to get more players onto it is a good thing, not just from my standpoint, but from that of everyone who plays.
You've even talked about how if you want to play with your friend, both need the remaster. YES.
That gets more people into the remaster, boosting the playerbase.
Notice there is no mention of removing the xbox 360 version from the store. I get they might eventually just because that might seem weird to some people, but really there's not much need. Yes, it's BC, but there's not near as much incentive to split the fanbase there, so removing it really isn't as important. And lo and behold, they aren't doing it.
I don't know why you think they're not removing it out of "courtesy for the fans." I mean, duh, it's not purely for that. It's so that new players want to play the game. If you had two versions of Halo, it would make sense to only have the new version sold, so that new players have motivation to buy the new one instead of the old one, and keep the playerbase in the best version. New players are guaranteed to buy the new one, but if you want all of them to, then you need to make that the only option, so that people aren't put off by dying playerbases. Anything that can be done to keep that as high as possible is a good thing, and this is literally one of the most effective ways of doing that.
I don't see how their reasoning matters, but simply put, they aren't invested in gaming all that much. Maybe we'll talk about playing it in a month, a year or 5 years.
And I think it's quite obvious why friend #1 isn't keen on paying $20 again for the same product, and why friend #2 isn't keen on paying $40 for a 6 year old game.
Which is why I said wait for a sale if they are not in a rush....
Like, that's how this works. If the game is not worth $40 to you then don't play $40. Wait till it is a different price.
EDIT: and look, dude like. I do gotta concede. It's sucky to remove it. I'm not dismissing your plight. It's just personally, I feel like this is the best course of action for the greater good, negatives and all. I wish they would release this for free, but I understand why they aren't. And with that as a given, this seems like the wisest course of action in my view.
