Chatzi Kaddish following Kerias HaTorah

How come according to MA an Oveil is not the one who recites Kaddish after Kerias HaToruroh?

Rallis

In short, it belongs to a shliach of the tzibbur, not an individual aveil. Like, for example, the kaddeishim after Yishtabach or after shmoneh esreh are not said by an aveil who is not the shliach tzibbur.

See the excellent and very comprehensive teshuvoh on the topic by Rav Hamburger shlit"a in Yerushoseinu I, pages 113-125.

Litvak