I think it was effective in that it showed how mind-bogglingly stupid
this version of Jonathan Kent was. He was a man who lived in fear and who, for all his rhetoric about how his son would achieve great things someday, spent his life teaching his son to be afraid to use his abilities for fear of discovery. If this Jonathan hadn't held his son back, then Superman probably would've been a more established and seasoned hero before Zod showed up and would've been more capable of standing up to him without letting a whole vast metropolis get destroyed and probably millions of people killed. Heck, if you ask me, Jonathan was as much the villain of MoS as Zod was. (And Jor-El was the actual hero, with Clark/Superman as an occasionally helpful sidekick.)
Not to mention Jonathan's added stupidity in that scene of telling people to shelter from a tornado under an overpass. That is absolutely the worst advice you can possibly give in that situation. The overpass concentrates and intensifies the wind, it keeps you from running if the tornado comes right for you, and clustering there can block emergency vehicles.