one of the reasons the 17th amendment passed in the first instance is that there were a number of scandals in which people essentially bought Senate seats by bribing legislators. Second, there is a risk (also present before the 17th amendment passed initially) that state elections would become little more than proxies for the Senate election.
I believe the corruption argument was a progressive idea that too many states bought into without sufficient evidence or research into the long term consequences. The best example I can put forward would be like the US reacting to the so called war on women, by killing off the Republican’s instead of the party that started the war. Look at how fast the seventeenth went from idea to ratification, and now we are reaping the whirlwind.
The second issue I do not see as a problem as long as the Senator’s are doing their job of representing the State instead of glorified Representatives of the people. The House of Representatives does that job just fine. Prior to the ratification of the seventeenth, the states could do what they wanted with it’s senators ie not send one or two, or recall them for failure on the job, or whatever.
It also needs to be recognized that the original move for the seventeenth failed to change the elected term to correspond to the Constitution. Representatives of the people serve a two year term not a six year term. Representatives of the State, serve a six year term, and that in my opinion makes the entire seventeenth unconstitutional.
Sometimes, I wonder if such vote-buying scandals were the result of an 1866 law that required that a Senator be chosen by a actual majority of state legislators, rather than by a method each legislature deemed fit. It seems logical that getting that majority requires more wheeling and dealing than getting, say, a simple plurality.