RFID: Why is inductive coupling used instead of EM waves for LF and HF systems?
No, the reason for inductive coupling wins over EM waves for RFID systems is better efficiency at nearby distances. Inductive coupling is a much better way of transferring energy over a short distance. For (really) long distances, EM waves win the race over inductive coupling. 

So, it has nothing to do with antenna sizes or reflection.