It's actually both. The Captain America of the 40s and 50s was nullified into "Not the real Steve Rogers" despite there being about 20 years between the end of World War II and Avengers #4 (published in 1964). So 20 years of readers were told that the Cap they remembered or read in-between wasn't the real Cap i.e. the one who punched Hitler on the cover. The reason Kirby and Lee felt they could do that was because those stories were widely seen as not especially good and the readership and fandom for that version of Cap wasn't sizable enough to count. So they introduced Cap in a block of ice whose last memory was a mission near the end of the war, nullified those interim stories, and then Englehart and others came in and made that Cap into a villain knockoff.
The quality of the story always does matter in such situations as these.
Arguably Batman. Since the 70s is widely considered the start of his best period in overall terms of comics writing. And since the 70s, Batman in the comics hasn't really had a bad decade. That's fifty years of consistency. Wonder Woman's a character whose iconic run, George Perez's came in the 80s. Overall Marvel Comics as a brand is 60 years old. Spider-Man is a new character who in less than 15 years (1962-1975) closed the gap between him, Superman, and Batman to become a zeitgeist hero. Superman vs. The Amazing Spider-Man, the first Marvel-DC crossover published in 1975 was Peter's coronation in that regard.Is there any comic where the very best work - work that vaulted over the impact of its most iconic eras - came four or five decades in?
My analogy framed your defense and excuse of shoddy writing as ridiculous via reductio ad absurdum. Saying that we can't criticize the Clone Saga for wrecking the continuity because "If they didn't do it someone else will" is utterly illogical. If you apply that in a real-world context then virtually every bad action by humans done to other people can be justified by that excuse.Your analogy frames the actions of the creators involved in the Clone Saga as terrorists deliberately visiting harm on a character and a comic.
The Clone Saga wasn't necessary, it wasn't inevitable, it wasn't willed by the stars, nor was it driven by any real concerns and fears. When Kirby and Lee brought back Cap and nullified the continuity it was driven by real concerns throughout. They got back one of their most iconic characters, they freed him of continuity and baggage that they no longer wanted to deal with and that had become embarrassing, and it was justified by lack of sales and interest. Nothing of a similar nature was the case with Spider-Man at the time of the second.
The story didn't get away from them. It was bad in conception and ill in intention from the very beginning. It should never have been allowed.They simply told a story that got away from them and, in the end, just didn't work.
For bad writers undoubtedly it would be hard. It wouldn't have been hard for writers of the other kind.Once enough stories have accumulated and the continuity is so top-heavy, it's going to become harder to keep telling satisfying stories that also maintain continuity while also keeping a desired status quo.
In the case of Bucky, well that's the pudding in the proof since that was a backdoor which allowed Ed Brubaker to bring him back and work with that.
In the case of Ben, there's a funeral and gravestone. There are multiple comics showing Peter and Aunt May visiting his grave, even in the Lee-Romita era. There's also a narrative reason for why we don't see Ben's death. Peter wasn't there when it happened and the story of AF#15 demands that we stay with Peter's POV as he learns of his Uncle's death and finds out the twist at the end about the Burglar. There's a narrative and emotional reason why the defining memory for Peter of his Uncle's death is the panel where he lets the burglar pass him by (as confirmed in stuff like No One Dies) rather than the Burglar shooting Ben. To do a panel where we see Ben shot from say Aunt May's POV, would upset that connection and the impact of that moment.