Is that really true? Or was it just that people didn't want that much legislation before Wilson and the Roosevelts came along? Cleveland and Harrison didn't want to do much legislation-wise, and voters didn't want Congress to do that much either.
Twenty years later, voters and the people they elected were in a very different mood. One of the things they wanted was popular election of Senators, but if they hadn't gotten it, wouldn't they have gotten their way through the old system, as they did under the new?
If the Senate hadn't become popularly elected, another amendment probably would have reduced its powers, since bodies that weren't popularly elected tended to be regarded as not fully legitimate in the 20th century. When we were passing the 17th Amendment, Britain was restricting the powers of their unelected House of Lords. Something similar could have happened here.
And if we go back to the old way and let state legislators choose their US Senators, the power of the Senate would probably be reduced. Countries that do allow bodies that aren't popularly elected to have a say in legislation usually make it clear that those bodies are second class in comparison to the popularly elected house.
The notion for popular election of Senators in the 20th century also coincided with the rise of Marxism as the ideal utopian government. One step toward that utopia was characterized by the promotion of a Democracy instead of a Republic.
Here of FR we like to call out politicians and journals for regerring to our government as Democratic. We at FR jump to make comments correcting any article calling us Democratic. “We have a Republican form of government,” is a common comment in reply. But the 17th Amendment took us one step AWAY from a Republic to a Democratic Republic. I shudder to think of more amendments that might further remove us from the Republic. Think: an amendment removing the Electoral College.
We can only restore our true Republic by repealing the 17th Amendment.