During the long span of development of my both roguelike projects I've been waiting for some great roguelike to appear, but it has not happened yet. It is a bit weird if you ask me, even there are many reasons why we don't have more roguelikes.
I think the numero uno reason is that they are difficult to create. I should know it, and I actually do. Even to have any kind of hope to release a major roguelike you need to grow up as a programmer if you already are not a good one. You need consistent planning and results that don't break up later.
But surely there are plenty of good programmers in indie scene? Well, my opinion is no. Open source and indie developers are in fact often even worse than professional programmers, who in most cases don't waste their time to roguelike game development anyway.
Another important reason is money. It is possible to make nice amount of money from game development, but it's easier to do with game genres that require way less time and work. Most game types are much easier to create compared to roguelikes or even traditional role-playing games (which are also quite hard). Some people are developing commercial roguelites which are light-weight roguelikes, because there is a market sector for them, but obviously they are not roguelikes.
Even after all these things I'm still puzzled about the small number of modern roguelike games, because I surely am one of the guys who would like to play a good roguelike game. There is ADOM, but it's a boring game with way too much grinding. DCSS is difficult and the developers seem to make it worse all the time which is quite hilarious, but then again it was never their own project as far as I know. The mindblowing thing is that we have games like Nethack as a great legacy, but building on top of that it would be possible to create far better roguelikes.