I love roguelikes and I like to play them, not only the major ones but also the smaller, uncompleted, abandoned ones. I think it's very satisfying to learn how to immers and adapt to new world logics and create tactics to compete with a new challenge every time I start to play a new roguelike.
The only problem that sometimes keeps me away to start to play a new game is control keys: every roguelike seems to have a different key set!
So everytime I know I have to print a page with all the keys and then learn again how to interact with a keyboard in a new world (but performing the same actions).
And if this is a little-medium problem for me (a roguelike lover), this is a bigger problem for people who know and like only one major roguelike; those persons may be fully unincentivied by this problem and consequently kept away from other games. Even from other major roguelikes, because if you take for example Doom Rl, Ivan, Adom and Angband you'll notice that they all have very different keyset. Two friends of mine love, love, love adom but never played other roguelikes, and I think it's just for this problem.
In my opinion, a very important thing for the whole roguelike community could be to create a general standard about control keys for the commands present in almost every roguelike (take stairs, get item, equip, inventory, attack ranged, pass turn, dip item, skills..).
A sort of "esperanto" between the major games keyset.
Not something to follow strictly (even because some roguelike has some actions that don't exist in others), just something to know and can be really, really useful for the gamers, the developers, and the roguelike community itself.