The general consensus these days seem to be that simpler interfaces are mostly better. Each game/UI needs to find its own balance, of course. I guess one of the main selling points of a complicated key set is that it makes the game smooth to play once you've mastered the keys, so that it even makes sense (in a twisted sort of way) eg. to have separate commands for wearing armor, jewelry, and weapons. Also, having more involved commands may open up for more complex item interaction – although I'm still waiting for the game where you can eat a scroll.
Personally, I aim for a very simplified key set in my own game, but using context-sensitive menus, so that might make the UI less smooth to some tastes. Basically, there's an always visible list of available commands in a menu that you can enter and navigate, or use 1-9 as shortcut keys. If you're next to a door, your basic options might be (1. open, 2. bash), next to a person (1. attack, 2. chat). It has its charm, such as if you learn a skill to pick locks, that option will automatically appear in your menu at appropriate times. Less elegant the fact that it varies which key is used for which action. I've tried to make up for this somewhat by having a shortcut key which always attacks, and one which picks the default environment interaction (open door, pick up item, etc). I'm even considering letting the player assign custom shortcuts to particular actions. That way, people who think it's a hassle to move their eyes from the map to the menu can elect to play with "o" for "open", "c" for "chat" etc.
At the end of the day, just design what best suits you and your game. If you have a gazillion keyboard shortcuts to memorize, though, a lot of people will think you're being old-fashioned.
 And consider that edible scroll I hinted at earlier. If I wanted that in my game, I'd have to explicitly display the option, effectively making the "puzzle" obvious. On the one hand, that takes away some opportunities to let the player be inventive. On the other hand, I guess that puzzle in particular would actually be bad RL design anyway, since it has zero replay value/challenge, and risks just putting unspoiled players at an arbitrary disadvantage.