I've never really understood the complaints about "splat bloat," to be honest. If you don't like a book that was released after the game came out, simply ignore it. Nobody is forced to include that content in their game.
I think there's a lot of things historically and culturally that contribute to that conception/problem. As far as I recall, 2e had plenty of splat, but fewer DMs seemed to feel like they had to include or allow all of it. To the contrary, it seemed like most DMs were very picky about what they allowed or not in their games (even if they were collectors otherwise.) To a large extent, I think it was because supplements seemed targeted at DMs more than players (even the "Complete" books, IMO.) I didn't know very many 2e players with huge libraries that weren't also DMs. For me, this indicates that [MENTION=6680772]Iosue[/MENTION] is basically correct in his assessment. Additionally, many 2e supplements (non-Realms anyway) contained alternative classes that were strictly weaker than their "core" counterparts but much longer on flavorful abilities relevant to their setting.
That seemed to change with 3e and the OGL. I'm not sure why, but I think it was the vast modularity of things like spells, feats, prestige classes, etc. that were so over-produced in 3pp. A setting or campaign guide for 3e could and usually did include vastly more discrete units than a similar book in 2e. It was much harder to look at a book and analyze all those fiddly bits, and after all it was all
supposed to be compatible. I'd imagine that would apply to authors as well. There really wasn't any good objective way to tell if a feat or spell was "too powerful" or not. Also, many of the books were obviously aimed at players, not DMs. Socially, people didn't want to tell their players "no" after they'd spent $20 on a new splat book. Additionally, "stronger" options have much broader appeal to players than DMs. IME, it was very easy for "kitchen sink" or "sandbox" campaigns to get wild very quickly. I had much better luck when doing things like "core + book X" and strongly enforcing an atmosphere or attitude on the campaign. I'm not suggesting that you needed to railroad, but you did need to recognize that the core books made a lot of assumptions about setting that would lead to a pretty gonzo game, especially for the so-called "tier 1" caster classes. (Which was only made clear in the fine print.)
I can't personally say too much about splat bloat in 4e. It would seem to me, as others have perhaps suggested, that 4e splat was much more about adding "breadth" rather than "depth" or power. Given that 4e (uniquely for D&D) had a fairly clearly defined power curve, that makes some sense to me. I imagine it
could be, if the the group divided for and against some aspect of relevant flavor. Whether that was problematic for groups or not, I dunno. I haven't really heard of it being so.
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