As long as the implementation of an easier mode (as i said, without a straight out "easy mode" with 200% health etc) does not hurt the whole game, there are no reasons to be against it, aside from being elitist pricks.
Why people think elitist is an insult, I'll never understand.
There is no way to implement an easy mode where I would not have to deal with it at some point. If I see it, I'll have to choose to not to pick it despite it being the strategically superior option (as relative to "reaching the end point") and then push the existence of it to the back of my mind. This is a hideous activity that I hate doing with every game (and boy do I have do it a lot): forcing myself to ignore a side of it that is abominable (in this case, restraining myself from power). The upside is that unlike a broken mechanic found within the combat system, it might be easy to ignore unless it is quite pervasive (don't get me started on games which force you to use quicksaves). I've become quite good at ignoring it, I think most people have if it ever bothered them (I think you would have to have some form of appreciation for arcade classics in order for that to develop), but I can still recognize that I'm doing it.
So here in a parallel universe I'm walking up to Dark Souls and it is going to be a testing and terrifying experience. Imagine it like a mountain, a true journey. But then I look to my left and there I see an escalator for dopes. Cue deflation. I'm suppose to take this game more seriously than it does? Well I have to if that's the case. I have to play pretend a little harder than I did before. I see this as a form of desecration to a piece of art, and it is distasteful to me. Adding an easy mode to Souls games would be a particularly egregious example too, backed by some despicable logic. Rather than to standing to see art eye to eye, people would pull it down to their lowness. But hey, they need to sell copies. I guess I can understand to some form and I've become quite good at adding rules to make a game fun. If the Souls games, among other games, can get away it would suck for them to spoil that opportunity to not have to pander.
You know that deflation I had for "Dark Souls with easy mode"? I still feel that to some extent when I look at the game-breaking co-op, the multitude of exploitative tactics, and GRINDING. So people want to take that feeling I have for Dark Souls now and make it harder to ignore. At this point I'm busy trying to ignore the fact that Dark Souls already has an easy mode.
Another problem that comes from this is that people (every reviewer, for sure) I communicate with about the game might have played a much worse version of the game. That is always confusing and, since I'm pretty invested in videogame criticism, concerning.
So this might be a small thing (and likely impossible for some people to "get"), but...
When it starts to fuck with the main game, then there's an argument to be had, indeed.
I think one of the biggest issues is the multiplayer, altough a good player with shitty gear, is still gonna destroy a bad player with easily obtained amazing gear.
Avoiding some crossover is very hard to do with 100% certainty and here in lies a more immediate problem. It doesn't take much thought to realize there is new found workload that comes with designing multiple versions of your game that have to be balanced to several skill levels (which is not exactly something that is concrete). Then you have priorities. Is the hardest difficulty going to be the most played? Well, it almost never is judging from stats I've seen. So why are going to focus on such a niche group, when you've already given gamers the easy way out? Does it matter if the hardest difficulty is well paced and balanced, when that safety net is always there and fewer people will be there to see it(not to mention the "achievements" thought process basically means people will allow themselves to be stepped on for a few gamer points)? How do you make certain, game-defining mechanics work consistently despite health, AI, etc differences? And don't get me STARTED on unlocking difficulties (fucking Bayonetta!). The best case scenario is that it is only very distracting to developers (actually the best case scenario would be easy mode being a trap for a 2 hour long BAD END route as I once wrote, sort of jokingly, in regards to how Dark Souls should add an easy mode).
History hasn't shown us that multiple difficulties is something to be jumping for joy over. I think the exception would be genres or series (Assassin's Creed, many western teams in general, JRPGs) which are so hopelessly caught up in pandering that a hard mode would be a relief. That's kind of where we are at with this unfortunate mechanism of game design: begging for scraps as it were to go along with the positives of modern gaming.
Another thing that concerns me that by not forcing gamers to rise up to a higher form, you are eventually allowing the medium to drop in standards. I don't have the facts to support it, so I won't lean too strongly on this, but I wouldn't be surprised if the state of difficulty and punishment of games today can tied to the introduction of convenient, accommodating difficulty settings. Because "Normal" sure as hell isn't "Normal". If a good "easy" were to exist, it would be one that before the game is through there is no difference between players of different difficulties. If I was a game developer and someone put a gun to my head, this is what I would try to aim for. I'll add modes called "Child" which results in the main character being turned into a monster two hours in (basically a joke on the player, maybe one that comes back to haunt them), "Adolescent" which is a little more friendly, but stops being so by 2 hours in, and "Adult" which would be the game. And that would be a painful compromise.
