Ɔn wʌn hænd, ɪt wʌd bi ˈiziər tu lɛrn, bʌt ɔn ði ɔðər hænd ju wʌd luz ði ˌɛtəˈmɔlədʒi ʌv ˈsɜrtən wɜrdz. Fɔr ˈɪnstəns, "criticism" ɪz ˈklirli "critic" + "ism" ˈwɛræz "ˈkrɪtɪk" ænd "ˈkrɪtɪsɪzəm" doʊnt lʌk æz ˈsɪmɪlər.
On one hand, it would be easier to learn, but on the other hand you would lose the etymology of certain words. For instance, "criticism" is clearly "critic" + "ism" whereas "ˈkrɪtɪk" and "ˈkrɪtɪsɪzəm" don't look as similar.