mg"a

I assume that your question is that we poskin that Shma is D’Orayos and that therefore sofek D’Orayso Lechumra.

That being said, R’ Moshe writes that the Chofetz Chaim poskined like the Gra [and that the Gra poskined like the Gra].

The Chazon Ish also poskined that we can rely L’chatchilo like the Gra.

So perhaps the real question is why the Chazon Ish, the Chofetz Chaim and R’ Moshe did not think that this was a sofek and poskined L’Chatchilo like the Gra.

R’Aharon Kotler and the Steipler were makpid on the zman of the Mogen Avrohom. Do you think it is a problem for people who rely on the psak of the Chofetz Chaim, R’ Moshe, and the Chazon Ish?

Why isn’t the hamon am machmir like the magen avraham if you said shma by that zman wouldn’t you be yotzei l’chol hadeios.

Because the hamon am isn’t necessarily more makpid on being yotzei l’chol hadeios than they are on a few more minutes of sleep.

well, it really depends whom you consider “hamon am”, most of the hamon am I’m surrounded by, the majority is makpid for Magen Avraham l’chatchila, only some would rely on the Gr”a.

BTW, the Chabadnik’s are also relying on that second zeman, cuz the Shulchan aruch harav (Tanya) also accepted that zeman.

Better question – Why are people not makpid on the Mogen Avrohom’s zman for Krias Shema which is M’Deoraisa, and would never be maikil like the GR’A on Erev Pesach for Sof Zman Achilas Chometz – which is only M’Derabanan?

You would think that someone who ate chometz after the MG”A zman on Erev Pesach was a shaigetz.

Or they feel that the Shittah of the Magen Avraham was completely Nidcheh by the GR”A

It wasn’t.