To some extent, I can understand why 4e strikes people as being similar to 1e. However, I'm not sure the main reason for this has been properly articulated or understood thus far.
1st edition evolved from tactical miniatures combat and was specifically designed to add role-playing elements to this type of combat. 4th edition was also specifically designed around tactical miniatures combat, albeit the type featured in MMORPGs rather than the more traditional wargames 1e sought to emulate. So certainly the emphasis on exactly where each figure is at any given point of time is highly reminiscent of 1e.
The relatively small number of options available to low-level characters in any given round is also very reminiscent of 1e. Such characters, if spellcasters, typically had a few spells they could cast but were otherwise forced to rely on at-will attacks (like slings and darts). Low-level characters in 4e also have a few spells they can cast and are otherwise forced to rely on at-will attacks (like magic missile and ray of frost). The 4e character may be "more magical" in a certain sense, but the in-game impact is largely the same.
That said, however, I'm not sure how well similarities like these really capture the overall feel of the game. To me the key point of departure is 4e's strict separation of tactical role-playing elements like magic missile from strategic/social role-playing elements, and the requirement that parties pay a ritual cost when opting for the latter course. This very much puts the wind at the back of those seeking a Diablo-type role-playing experience, as they're able to use all of their tactical powers without sacrificing gold. Whereas in 1e the wind was if anything at the back of those making their first tentative moves away from the battle mat, with many players exploring for the first time how one might go about running a gaming session with nothing but imagination. Admittedly miniatures were very commonly used in 1e and 4e both, but I don't see the flavor of these two editions as being nearly as similar as some people seem to believe.
One particular alleged similarity which I think people have exactly backwards is this one:
The bottom line, I think, is that people who enjoyed the tactical-combat aspect of 1e can rightfully see 4e as being a return to what they knew and loved about (A)D&D, but those who liked 1e for other reasons can be justifiably puzzled by the notion that 4e represents a return to those halcyon days.
1st edition evolved from tactical miniatures combat and was specifically designed to add role-playing elements to this type of combat. 4th edition was also specifically designed around tactical miniatures combat, albeit the type featured in MMORPGs rather than the more traditional wargames 1e sought to emulate. So certainly the emphasis on exactly where each figure is at any given point of time is highly reminiscent of 1e.
The relatively small number of options available to low-level characters in any given round is also very reminiscent of 1e. Such characters, if spellcasters, typically had a few spells they could cast but were otherwise forced to rely on at-will attacks (like slings and darts). Low-level characters in 4e also have a few spells they can cast and are otherwise forced to rely on at-will attacks (like magic missile and ray of frost). The 4e character may be "more magical" in a certain sense, but the in-game impact is largely the same.
That said, however, I'm not sure how well similarities like these really capture the overall feel of the game. To me the key point of departure is 4e's strict separation of tactical role-playing elements like magic missile from strategic/social role-playing elements, and the requirement that parties pay a ritual cost when opting for the latter course. This very much puts the wind at the back of those seeking a Diablo-type role-playing experience, as they're able to use all of their tactical powers without sacrificing gold. Whereas in 1e the wind was if anything at the back of those making their first tentative moves away from the battle mat, with many players exploring for the first time how one might go about running a gaming session with nothing but imagination. Admittedly miniatures were very commonly used in 1e and 4e both, but I don't see the flavor of these two editions as being nearly as similar as some people seem to believe.
One particular alleged similarity which I think people have exactly backwards is this one:
The superiority of multi-classed characters in what we would now call "heroic" campaigns was so severe in 1e that it sometimes became difficult to find any single-class characters. And those who were single-classed were typically human fighters who planned to dual once they reached 7th level, eventually enjoying the complete use of all fighter class features plus the complete use of mage or thief class features too -- ideal for paragon-level or epic-level adventures. In this the contrast to 4th edition could hardly be more striking, as you can never gain most features of your second class no matter how much you might wish to do so, through multiclassing or dualclassing or anything else.[*]Single-classing is DEFINITELY stressed over multiclassing.
The bottom line, I think, is that people who enjoyed the tactical-combat aspect of 1e can rightfully see 4e as being a return to what they knew and loved about (A)D&D, but those who liked 1e for other reasons can be justifiably puzzled by the notion that 4e represents a return to those halcyon days.