Our Framing generation and earlier philosophers distinguished between liberty and license, between ordered liberty in a civil society and abuse of liberty. The former promotes social cohesiveness essential to our happiness, while licentiousness divides our community into squabbling factions that may eventually disintegrate our (feeble) republic.
BTW, if Senators were appointed by the States, do you think Congress would be pushing the States around like this, over gay marriage and other issues like Obamacare?
Absolutely not. That’s why I’ve always advocated for the repeal of the Seventeenth Amendment.