There is an obligation to be maavir sedra too, but most people don’t spend more than an hour a week doing it. We don’t find talmidei chachamim who don’t know tanach; they do! But the stressing of it in day schools and MO yeshivos leads to neither understanding of tanach al pi chazal, nor success in learning altogether. This can be seen by the amount of MO graduates (the half who are even frum) who learn on their own or at all after their year of fun and games in eretz yisroel. They might listen to inspiring speeches encouraging them to be good older brothers who take their younger brothers to movie theaters (i heard a motivational MO rabbi speaker person say this once) but very few learn in a semi-serious (i.e. daf yomi) context.
