Well again, I don't count games that were poorly designed. Exploration is certainly important, and modern games seem to be lost on that fact BUT if it's impossible to know what to do in a game without consulting guide books I would argue that it isn't hard, rather it's just a crappy game. I think the best example I can give is one of the Castlevania games (The third I think?). There's that one portion in the game where you have to go to a dead end, equip this obscure crystal item and kneel for 10 seconds to proceed. The clue in the game is poorly translated so it isn't of any help. So yeah, that game isn't hard, it just has issues.
I mean I look at a modern game like Assassin's Creed, and the enemies are so tiny and look so similar that without the goal/map/eagle vision system, I don't think the games would be playable.
I just give this particular issue as a specific example because if you look at the list of features you linked to, more than half of them are just design/programming issues.
Maybe "Nintendo Bad" is a better term? I mean I hate to use it... I think the old NES had the highest ratio of quality games to crap than any other system, BUT designers were still learning back then, so a lot of mistakes were made.
I'm not saying that there weren't hard games on the NES, there were quite a few, but there are still hard games today... they just don't sell well because these new generations of gamers are big babies. Back in the day if you couldn't figure out a level you kept at it and hoped that in a month or so it'd be featured in Nintendo power. Now kids give up and immediately consult gamefaqs.