The Redskins are the 14th most valuable sports franchise in the world. They are huge in their regional area. Their 2 decade slide has corresponded with a slide from #3 on the list to #14, but otherwise, they still sell a lot of merchandise. This is ideological, not economic (otherwise, Dan Snyder would have changed the name decades ago; he's only doing it now because it is finally hurting his bottom line and chance for a new stadium).
I saw an article a few days ago listing the top ten franchises in terms of their jersey sales. The New York Giants were #1, which shouldn't be a huge surprise because they play in the biggest metro-area market in the U.S. The Dallas Cowboys were somewhere around #4 or #5 -- which did surprise me (I thought they'd be #2 at least). The Packers, Eagles, Steelers, Ravens and Patriots were also in the top ten, if I remember correctly. The Redskins were nowhere to be seen.
I'd be shocked if Washington was even in the top TWENTY among merchandise sales right now, since their sales seem to be tied almost entirely to their on-field success and the presence of an iconic name on their roster. Right now they have neither. They probably have very little appeal outside their own fan base, and their color scheme doesn't have appeal to nitwits who don't even follow the sport but buy jerseys anyway because of the "cool" colors -- like the Ravens, Raiders, and any other professional team with black colors.
From a few years ago: