Interesting mention of opposition to daf yomi based on more traditional strictures, like hevros tehilim/mishnayim/etc
It seems that pro-daf rabonim (not just R Shapiro, but those before and those who followed) responded to the needs of emerging modern Yid who is exposed to newspapers/philosophy/literature/techology/science, while those against were guarding the innocent balabatim. So, both might have been right for different countries and communities. This is similar how R Salanter marveled at shiurim in Germany where ladies showed up to listen. He said – if I were to do this in Lita, I’ll be kicked out.