Stock D60's still use 30 spline outers and their respective lockouts are usually weak too. I broke both under my 4K buggy with little effort on 37's. I've since been running 42's with 35 spline outers with not issues, but that's not a stock D60
Yes, driving easy saves parts. Quite simply, having to be easy on your parts makes the rig less capable. Many here have wheeled with me; I'm not a throttle down, close your eyes and hope kind of driver. There are times your tire will get a little bound up and you have to drive through it, there are times you have to throttle up an obstacle.
Any time you have to decline to do that to save your axles you'll realize the vehicle is less capable.