Background
In the United States, the 17th amendment changed the election of senators from state legislatures to the popular vote:
Amendment XVII
The Senate of the United States shall be composed of two Senators from each state, elected by the people thereof, for six years; and each Senator shall have one vote. The electors in each state shall have the qualifications requisite for electors of the most numerous branch of the state legislatures.
When vacancies happen in the representation of any state in the Senate, the executive authority of such state shall issue writs of election to fill such vacancies: Provided, that the legislature of any state may empower the executive thereof to make temporary appointments until the people fill the vacancies by election as the legislature may direct.
This amendment shall not be so construed as to affect the election or term of any Senator chosen before it becomes valid as part of the Constitution.
Of all the contemporary reasons for this amendment, one of the side effects was that more rural areas of states would have reduced power:
Ironically, however, big city party machines supported the Seventeenth Amendment, largely because state legislative apportionment gave greater representation to rural areas due to districting decisions in the absence of “one person, one vote” and because machine-controlled cities could more easily mobilize voters. Many big special interests supported it as well.
On a national context, this precise side effect was one of the main motives the founding fathers stated when creating the electoral college. Historians have also argued that the other stated issues of electoral deadlocks and legislative corruption were not widespread enough to serve as a de facto motivation for the amendment. This has lead me to ask...
Question
Given a key motivation behind the electoral college, why did the mirroring concern of small district representation not cause a widespread issue during the creation of the 17th amendment to the United States constitution?