I rarely use a tripod when shooting my landscapes,probably as we ( wife and I ) do walk quite a few miles and it gets a bit heavy after a few hours,well it does when your in your sixties.Having said that if we are going to a specific place that is going to need a tripod,waterfalls on slow shutter speed etc then I will take the tripod with me. I have to admit though there have been a number of times I wish I had carried it with me.

In my days as a wedding photographer virtually everything was shot on a tripod for more reasons than just camera shake though.

A few years back I nearly always took the tripod but it is now all getting a bit heavy with the camera,spare lens's,coffee,sarnies etc. 
Getting old sucks but I dont wish the alternative :-)

Eddie