I think there is a fundamental misunderstanding when it comes to what qualifies as a "hard" video game, and what is merely a "challenging" one. People are so quick to label games as "hard" if they die on them or whatever, and I think that in itself shows how much games have changed, and how the current generation compares to the older ones: having played video games for almost a decade now, it is extremely rare (in fact, there has been only one occasion where I've thought this, which I will get to) that I think "Damn, this is a hard game" if I die.
People go on and on about how Demon's Souls and Dark Souls are difficult video games. Neither of those games are difficult, they're just different to what modern gamers are used to, which does NOT make them hard, or even challenging. The Souls games are a good modern-day example of video games being a learning experience: you will die a lot, but just because you die a lot, does that make a game hard? I would say no, as strange as that may sound. But, allow me to clarify: back in the day, video games were often challenging, because they tended to have one set way of doing things, and were damned unforgiving if you got it wrong. Dying was brought about as a result of your own ignorance, and it was entirely avoidable if you did things in the right way. Once you learned what that right way was, it was all too simple to overcome it. Something that has been all-but eliminated in modern games, with difficulty modes just adding damage or health or whatever, but requiring no real skill to overcome. You're given much more leeway, and that is why it is so easy. Contrary to popular belief, an increase in enemy health and damage, or a handicap you didn't have the first time through, does NOT make a game hard. What makes a game hard is unpredictability. Where enemies have no set attack patterns, or telling signs for what they're going to do next, and where there is such a minimal margin for error that it takes you a very, VERY long time to figure it out. THAT is what a hard video game is, and it is something that is extremely thin on the ground at the moment. Pretty much any game you can master within five minutes these days.
So this, then is why Dark Souls and Demon's Souls are not hard: because they're too damn predictable, after that initial death at the hands of an enemy. Having just finished Dark Souls, I can say I was extremely disappointed: no boss killed me more than twice, because once you've memorized their attack patterns, and you know what to look for, that's it. You can beat the game. Automatically dying because you slip up doesn't make a game hard; in my opinion, that is how games SHOULD be.
Another fantastic example of my point is Castlevania: The Dracula X Chronicles. This is easier to illustrate, because it's a side-scrolling platformer in which your maximum movement speed is walking. As you go through the levels and become familiar with the enemies, you can tell what their next move will be, and so you can avoid it. It's entirely feasible to go through the game without getting hit at all, but you're likely to die multiple times nonetheless. Hard? No. Challenging, until you've figured it out? Yes. See the distinction? Hard cannot be overcome through skill alone; it requires perseverance and luck. Hard is unpredictable, not just unforgiving. This unpredictable factor, in my opinion, is what has been removed as games have moved through generations, for whatever reason, and this is why there are complaints that games aren't hard anymore.
I think one of the main reasons for this is the need to address balance. To overcome something that is hard, you usually need a little luck, and having to rely on luck rather than skill to overcome something in a game is ANNOYING. Take Star Ocean: The Last Hope International as an example. A very good one. Platinuming that game is an absolute nightmare, because a goodly percentage of the battle trophies rely on luck, rather than skill. A game that requires only skill to beat can NEVER be hard in my opinion, because skill is easily acquired, and once it is the challenge goes away. But how much of a factor should luck be? Since most developers don't seem to be capable of deciding this, they opt to take it out entirely. You can't have it both ways, I suppose.
But the problem with modern video games is that they treat gamers like we're all brain-dead morons or something, and as soon as a game comes along that actually requires us to think a little outside the box due to a lack of prompts (like the Souls games) then they're automatically considered harder as a result. This is probably another reason why older games are considered harder: because there were no such prompts back in those days. I don't see WHY we have to have all this information spoon-fed to us, it'd be a lot more challenging if we had to figure this out for ourselves, and challenging is the first step towards being truly difficult. It can't really be hard if you're told what to do, can it?
The only game of this generation I would say is hard, without any sort of handicaps or difficulty modes, is Resonance of Fate. That game required an immense amount of strategy, and it really let you have it if you messed it up. Every move needed to be calculated, and whilst the difficulty was somewhat uneven, overall it was a real nightmare at times. The randomized battle fields made each situation different, so whilst you could rely on skill, you could not just follow a set pattern, because the circumstances were always different, and if you made too many mistakes, that was that. Critical Condition in that game was a death sentence. It's a fantastic example of a hard game on a current generation console...and the only one I can think of right now. xD
Sure, you can always make your games more challenging by handicapping yourself, but in my opinion you shouldn't have to do that, and when difficulty modes only even out the playing field much of the time, they don't really account for much. That's just my ridiculously long opinion on the subject. xD