The DC Metro sucks. Besides poor coverage, you also have a needlessly complicated fare system with no monthly passes, draconian rules about food with equally draconian enforcement, and bathrooms in every station but you're not allowed to use them.
Part of the original rationale for not opening the toilets to the public was concern about crime. The DC Metrorail system was planned and laid out primarily in the late 1960s/early 1970s (with route tweaking continuing for many years afterwards), and that's the period when the New York Subway was at its low point in terms of crime, graffiti, etc. DC's planners were petrified that the system here would wind up becoming a den of crime. New York had some restrooms, but almost all of them were closed because of crime and supposedly because of homosexual activity, so DC's planners decided from the start not to offer public toilets. Officially the station manager is authorized to open the restroom in case of "emergency," though the station manager is also the judge of whether you really need to go. The only stop that has a regularly-accessible toilet inside fare control is the Huntington stop in Virginia on the lower level.
My wife rides the DC Metrorail to work. I used to in the late 1990s, but through the 2000s I drove, and we normally drive to hockey and baseball games because it's substantially faster. DC took "don't copy New York" to an extreme and designed a two-track system with very few pocket tracks and no provision for express service. Problem is, when a train breaks down or has some problem it snarls the whole line, and because there's a lot of shared trackage across lines, any such snarl ripples across multiple lines. I read a book about the system's history and the planners were apparently convinced that the system would be so reliable that breakdowns wouldn't be a concern. Massive failure on their part. It costs me $14 to park when I go to a hockey game, but we get home in 20 minutes (compare to 45 on the subway by the time we wait for the train, ride to our stop, walk to the car, exit the parking garage, and drive home) and the cost winds up being slightly cheaper than the subway when I add my rush-hour fare into the city (over $5.00), parking at the stop near home ($4.50), and the non-rush fare back home for both of us (I think around $3.00 each). For baseball games there's no comparison because I can park in a metered zone for less than $1.00 and be home in 20 minutes, whereas on the subway we'd have to change trains twice or else go way out of the way.
To me the main failure of the DC subway is that it's premised entirely on the suburb-to-city commute because that's what people did in the 1960s. Nowadays the suburb-to-suburb commute is at least as important, but the Metrorail system doesn't serve that unless you're willing to ride all the way to, or close to, downtown, then change trains and ride all the way back out. But trying to build a rail system to link the suburbs isn't easy due to cost and due to density—in order to make a Circle Line type thing cost-effective, it would have to link high-density areas that would generate enough business, but there aren't enough of those. This is the problem with trying to graft mass transit rail onto an already-developed area, compared to having the system grow with the area as happened in London and New York. Of course, that also means that it's not really fair to use London or New York as a model for what DC's Metrorail is or should be in terms of level of service, but I do think it's fair to criticize the designers for making some foolish design choices just because they were "anti–New York Subway." I mean, New York's first IRT line opened in 1904. Even if that system had problems—and it surely did—it was foolish to ignore 60 years of lessons about how to run a subway.
We do have a very extensive bus network but it's relatively under-used except in certain corridors, many of which tend to be lower-income or minority. A major part of the problem in that respect is simply that so many people in DC don't necessarily have a fixed 9-to-5 (or whatever) schedule and so cannot necessarily rely on making the bus at a particular time every day; also, when you're not convinced that the trains will be reliable, and your bus only runs once an hour, it's understandable why a lot of people shy away from making the subway-to-bus connection. I've been quite thankful for the Fairfax Connector bus on a few occasions when I've had to leave one of the cars at the mechanic overnight while they obtain parts, though.
On the whole I'm convinced that notwithstanding its flaws our Metrorail system is a benefit to the area. All I have to do if I doubt that is to look at the Franconia-Springfield Metro stop's parking garage. It holds around 5,000 cars. I assume some of those cars brought more than one person to the subway, so I figure if the subway weren't there, that garage alone would pour another 5,500 to 6,000 cars onto the streets. Then I multiply that to account for other suburban stops with big garages and I shudder at the thought of all those cars on the road.