Keep in mind a kezayis is the minimum shiur required. (the size of an olive not more)Ie the absolute minimum amount to be considred eating is a kezayis.
Do you build a sukkah 7 x7 tefachim and 10 tefachim tall? Do you measure out enough oil so menorah will only last a half hr? why settle for the absolute minimum amount of matzah needed to be yotzeh?