I haven’t followed Strasburg this year.
This kind of pitch limitation strategy has been evolving for quite a few years now in MLB with nearly all pitchers. Most starting pitchers nowadays are on a pretty strict pitch count, generally about 100 pitches per game – assuming they haven’t been injured or shelled before that point, that they haven’t been pinch-hit for (in the NL), and that they haven’t become tired or cooled because of rain delays, their own team’s offensive explosion that has them waiting too long before the next inning, etc., and also assuming they aren’t about to make history sometimes by pitching a no-no or even a perfect game. Young pitchers without several years of Major League experience are limited even further (such as Joba Chamberlain in the AL, before he was injured this year – not specifically due to his pitching, though) so that they can build up to that kind of level and pitch for longer in the season and longer in their careers.
Only a few old-school pitchers are left, such as Roy Holliday, who wants and expects to go the distance every time he starts.
The reason for limiting pitches during the regular season games is because the season for playoff teams is now so much longer, for one thing, that it simply wouldn’t be smart for team management to allow the guys who got them to the playoffs to be burnt out by the time they start that second season. But it’s also about the pitchers’ career longevity. You want to have young pitchers work up to a point where they can consistently throw 100-pitch games over time and for many years, without expecting them to do that right out of the gate. This is especially true of fireballers like Strasburg. And that describes “most young pitchers” these days. Few pitchers start their careers as knuckleballers and crafty “spotters” who can trick batters with sinkers, wicked curves and pinpoint placement anywhere around the plate.