DCA is great to fly in and out of (I live in DC proper), as it's close, isn't hard to get to, and has a Metro (our subway) station right in front of the terminal, and the airport is fairly easy to navigate once you're in. Dulles now has a Metro station, but it's still far away from the terminal and it's hard to navigate, with gates very far away from the terminal; other than the Saarinen architecture, everything else about Dulles is awful. BWI is even further from most parts of DC; there's an AmTrak station where you can catch a bus, but pretty much you're driving an hour+ and it's in the middle of exurban hell.

DCA is challenging for flights, though, as the approach from upriver over the Potomac requires a sudden bank to the right just before landing and the runway's a bit short (tonight's flight was coming in from the southern approach). The Potomac also has a lot of helicopter traffic, between the military (including POTUS/VPOTUS), US Park Police, DC Police, and civilian flights. DCA's natural advantages have put the screws to Dulles the last 20 years, and Dulles's inability to not suck hasn't helped. As a result, people (including Members of Congress) want more flights out of DCA, so flight traffic has steadily increased. There were two near-misses last spring: https://www.nbcnews.com/news/us-news/faa-investigating-colli....

Tonight's crash seems like a colossal screwup by the helicopter. DCA is too popular for flight traffic to cease, but I wouldn't be surprised by further restricting the flight corridors and helicopter traffic, more funding/staffing for ATC, and maybe a small reduction in flights.

DCA is just across the Potomac River from DC and thus large amounts of restricted air space. This makes take offs and landings at DCA challenging since all this restricted air space has to be avoided. DCA also has not space to expand to try to mitigate the risks. Congress has interfered over the years by attaching riders to legislation requiring the number of flights allowed in and out of DCA to be increased over the objection of the Metropolitan Washington Airport Authority (MWAA) who runs both DCA and IAD (Dulles). This despite decades of warnings that the number of flights posses a significant safety risk.

Regional airport authorities which run multiple airports such as MWAA generally spread the cost of improvements out across the multiple airports by increasing gate fees at all the airports they control to cover the cost of improvements at any one airport. Congress has forbidden MWAA to do so which has limited their ability to expand and improve IAD to lure airlines to shift domestic flights from DCA to IAD. IAD remains primarily an international airport with domestic flights in and out supporting that role. This is largely due to the higher gate fees at IAD.

It's in the middle of a city, with lots of restricted airspace just _seconds_ of flight time from it.

From what I've heard, it's a challenging airport to land at, particularly because one of the approaches has two sharp turns in it, and I think the main winds tend to be annoying crosswinds for the main runway. Also, the airport is surrounded by lots of restricted airspace because, you know, seat of federal government and all that.