To be honest, WB1.3 was much better than TOS, BUT TOS delivered its purpose more efficient and effectively than WB1.3. It was booting in seconds, provided basic funtions for 16bits, and was more easy to use. Atari was also more open minded in delivering multi-languange support for it. I was hired by them in 1990 and developed a Greek ROM. Also bear in mind that ST could boot TOS from floppy as well.
As I said, WB 1.3 was brilliant if you had a HD, but with the release of A500, WB 1.3 was cursed to remain an unexplored OS to most. I was lucky to have that work back then. I apparently collected enough money to buy me the HD for the A500 (an Alpha Data if I am not wrong).
This is a better explanation about what I meant up there... And I think it's 100% true....
This is a more appropriate