The reason why it is bad if u do ur cardio before ur weight session is that, u r wasting all ur stamina on cardio (in which aft intensive cardio, i dont think u would love to squat for 12 reps right?).

I usually do my cardio on my off day as i have limited training time in the morning. However if u have extra time, theres nothing wrong doing it after ur weight session (i would do it if i finish my weigh training earlier). However, during my fat loss period, most i will do 3 session of cardio in a week, but normally i will do only 1-2 session and there are all HIIT.

p/s: there would be 1 day in a week that i dont train at all, rest is important