One must consider the aircraft, the circumstances, the load, the runway conditions, the predicted performance, and the type of operation. In many operations, it's very wise to use all the runway. In others, especially operations in which one will have no difficulty remaining aloft following an engine failure, then runway behind isn't particularly relevant if adequate runway to stop or go lies ahead.
One must certainly differentiate between transport category aircraft, and everything else, but one must also look at other circumstances. Can the aircraft depart safely, using predicted and calculated performance, from the current intersection? If I need nine thousand feet to stop or go and there are fourteen thousand remaining, then I've certaily got more than enough. Taxiing the fulll length may create unnecessary ground handling problems or delays, may increase tire temperatures unnecessarily, and may mean an extended wait due to traffic which isn't warranted when the takeoff can safely be done from the intersection.
That said, all else being equal, I'll take full length whenever I can get it.