No, but this is my free time and how I use it. If I chose to do that during my vacations, no one would be "well poor you, you don't really have 4 weeks of vacat

No, but this is my free time and how I use it. If I chose to do that during my vacations, no one would be "well poor you, you don't really have 4 weeks of vacation a year, since you decided to pursue professional development during these weeks". People would simply say that I chose to use my free time to do these things, and some of these things are quite essential to my continued employment.