There's a whole bunch of assumptions here, I'll take them one by one:
- that players in later editions won't have henches and multiple characters just like in earlier editions. Why not? Just because the game makes assumptions doesn't mean those assumptions have to come out real.
True, and I don't think I actually mentioned editions.
In practice, though, I think that some of the assumptions made in later editions affect the mechanics in ways that make henchmen harder - for example, the complexity of character building and action resolution in 3E or 4e compared to AD&D or Basic.
that character development was any less important in older editions. In many cases character development has always been important. But it hasn't always had a mechanics aspect.
Well, I'm not assuming anything here. I'm
asserting that the centrality of character development has grown over time, and that game design - including PC build mechanics - have changed to reflect this.
If character development is
not mechanically expressed, then I think that levelling up will naturally be reduced as a focus of play. But I think there is at least some evidence - namely, trends in game design - showing that as characters become central to RPGing there is a
desire for their development to be mechanically expressed, at least in part.
that players/characters are going to stay on an adventure path once they start it. If they want to stay on a predetermined course then so be it, but if having just finished adventure 4 in a 9-adventure path they decide "screw this, we're going into the hills to bash Giants instead" then how is that any different from any other edition?
Well, at this point I think you're not really running an adventure path. I'm not certain, because I'm not an adventure-path guy, but my understanding of the typical adventure-path group is that there is a mutual understanding that the players will stick to the path.
Which means that building their PCs becomes one of their main elements of control over the fiction. (Because both situation
and plot have been largely ceded to the GM/module writer/)
And, of course, that a 9th-level Thief is getting ready to either start her own guild or take over someone else's. And she is - or should be - a whole lot richer than she was as 1st level, with all the benefits and drawbacks inherent. Also, she has probably met all sorts of influential and powerful people during her adventuring career and can try to leverage those acquaintances to her benefit.
I chose 9th level because the guild stuff doesn't come up, in AD&D, until 10th! (Though in Basic it's 9th, so maybe I should have said 8th.)
And yes, the high level PC will be richer and better connected, but I see this as more a matter of quantity than quality - after all, the 1st level PC can also be rich (in a relative sense) and well-connected (in a relative sense), with level gain just changing what this is relative
to. Whereas, in 3E, a 1st level rogue
can't be a relatively good swashbuckler - s/he has to wait to 2nd level to take Weapon Finesse.
In my view, this is the sort of mechanical difference that makes the desire to level more likely to come to the fore in 3E than AD&D. (Though as [MENTION=22779]Hussar[/MENTION] pointed out upthread, some AD&D PCs are also mechanically dependent on realising their concept - spellcasters, obviously, but also paladins, monks and to a lesser extent rangers.)