You may find some graduate advisors who have that habit of giving lots of positive feedback, but there isn’t one single graduate program. It really comes down to the professor, and there is very little way of knowing a priori whether a particular professor is of the “nurturing” sort that you desire or not. At the very least, even with the ones that are that way, you will be expected to start paving your own path within the first several years of the program. The entire point is to become an independent researcher. Basically, as soon as the class portion of the program is over, PhD programs are essentially completely in any meaningful way other than the scientific method. The degree of any other structuring again varies widely by advisor, not by school.