Lobbyists do a ton of information gathering work for the legislative process. How could you seriously consider a banking bill without having people in the financial institutions involved?
That's the nature of party leaders in two different branches trying to do what's best for their party in their own branch.
The public remembers the bad experiences with lobbyists because those cases are prosecuted and publicized. The everyday lobbying activity that helps the system run doesn't come to their attention.
Rather than compromise, parties are more likely to stake extreme ground knowing they won't get what they want because it allows them to communicate to voters what they stand for.
In any case, narrower representation has more power than broader interests.
The hot button social issues are really tempting to a candidate in Kentucky because the place is relatively unified on a number of those issues. I would be terribly surprised if candidates didn't give into that temptation this year.