The Nationals did the exact same thing with Jordan Zimmerman's injury last season. Rizzo and Johnson have said all year this was their plan and they're sticking to it.
The thing a lot of people don't realize is even without SS, (who's been great but he's had some rough outings as the season went on) the Nationals still have an excellent rotation. Gonzalez now is 18-7 with a 2.99 ERA. Zimmerman 9-8, 3.01. Jackson 9-9, 3.63, and Detweiler 9-6, 3.15. That's a rotation a lot of teams would love to have. And John Lannan, who got dumped into AAA, was very capable with a 10-13 record and 3.70 ERA last year. He most likely will take Strasburg's place in the rotation. he may not overpower batters but he'll be solid.
Then you throw in a bullpen where aside from the little used Henry Rodriguez, you've got seven relievers with five of them having ERAs under 3 and the other two about 3.50. So their pitching is not going to implode and crash when SS sits down. I really don't know why the media is making such a huge deal out of it. Would they want him pitching in the postseason? Sure. But if something did happen and he regressed that would be awful.
The great thing here about the Nationals is they were supposed to contend for a Wild Card but that's it. This season has been a blast. Now they're 7 1/2 up on Atlanta and are probably a season or two ahead of where they should be. They've gone through some terrible seasons but have drafted well, rebuilt the farm system and made some good FA moves. Plus they're very young, so it's not like they have a rapidly closing window either. If they lose in the playoffs it won't be the end of the world, they'll probably be pretty good now for a few years.
I've adopted the Nats as my NL team and I'm perfectly fine shutting him down, so are most of the fans I know and the ones calling in on local radio here too. In fact a running joke is that him sitting will hurt the offense more, since he's a pretty good hitting pitcher. (.260 I think)