I came to AD&D in 89/90 so it was 2e in full swing. Hungary being former Soviet Block, anything from the USA was hard to get.
There were some 1e books around thus we could glimpse some of the changes. We always thought that the main reason for the edition change was option (d): catering to the too conservative people's craze about certain names.
And I see the same pattern here as well. Most of the more profound changes are because now the company wants to cater to the very (too) liberal's taste. And for me that is a problem. I won't be opposed to system evolution, just don't let politics dictate the direction.
Looking at RPGs in a boarder perspective, edition changes are either minor incremental updates or big changes all the time. CoC - as far as I understand it - is more of an incremental change. I think we began to play around 4th or 5th edition, and only our GM (Keeper) knows the rules anyway. In Ars Magica, even the setting changed between editions (but the core of the engine and the board strokes of the magic system feels the same, at least in the 3-4-5 editions). And Star Wars, which I know is more of an intellectual property than an RPG setting, changes RPG system much too often (I played considerable amount during the d6 era, and some in the d20 era). So I'm fine with bigger and smaller changes too. Now I would not mind some bigger changes, thus a proper 6e.