Because we are today challenged on things, which in Teddy's day were still so sacrosanct, that they never really engaged Teddy's attention in a way to offset his focus on some legitimate complaints which did engage him.
Teddy's son, Archibald, was a stalwart Conservative in the late 1950s & early 1960s, in ways which reflected the dominant patriotic side of his father, as opposed to his father's sometime sympathies for the non-Marxist muckrakers.
As we wrote in “A Patriot’s History of the US,” Teddy’s main flaw was that the man did almost everything-—except run a business. If he had, no doubt some of his goofy Progressivism would have been curbed.