Many MMO designers I’ve talked to consider an on-screen map to be a luxury, a convenience feature for lazy people who don’t want to navigate “the real way,” whatever that means. These people tend to be really good at FPSes and think of maps as a bit of a crutch.
This is why it’s so important to identify your audience early on. If you’re going for the FPS audience, then having a map on-screen is in fact often considered a crutch. But these games are very difficult for many gamers to get into.
Women, in particular, tend to navigate by visual cues like maps and guides, rather than by directional orientation.
I’m not female, but for whatever reason, I have no innate sense of north or south or whatever. As a guy, I’m expected to have this ability, but it’s not something that can be learned. You have it or you don’t. So when faced with a game that doesn’t give me enough cues to tell where I am, I simply don’t play. It’s not snobbery — I just can’t play it. I am not the only person like this.
In the real world, I navigate by finding distinct landmarks continuously. In a game, landmarks betray me: textures and geometry get reused constantly, and soon I am utterly turned around.
When you remove the map and compass from your on-screen GUI, you remove me from your audience. You also remove plenty of other people. Does it matter? Well, that depends on your target audience. If you’re going for broad appeal, then yes, it matters. If you’re trying to hit the 18-22 male FPS-playing crowd, you should probably avoid the radar, because that’s what they expect. It boils down to knowing your audience goals.
So, what’s your target audience? Is it written down? Is it clearly delineated into one or more marketable entities? If you don’t know your audience, then you’re designing randomly. You might get lucky and design a game that an audience really loves, but more likely, you’ll make a hodge-podge and fail.