I get pissed off all over again, at the crappy job the air force did, bombing the structures at the various beachheads, especially Omaha beach, where the Americans landed. Sure, there had been deaths, american soldiers killed by bombers, that had the air force, excuse me, the Army air corps gun shy. But tons of bombs were dropped 3 miles inland, leading to "they sure killed lots of cows" remarks.
This is a very powerful movie, likely to bring tears to the eyes of most. But anyone that served, and knew the exquisite agony of having a friend in his 20's die, when most 20 year olds never have had someone they know die, for any reason.........are likely to feel the pain of the soldiers hit on the beach, even more.
Think about how the landing would have been different, if the pill boxes were gone, or if the tanks (the ones with skirts) had landed with the troops.
Meanwhile, a few miles to the east, the English troops landed unopposed, their biggest worry, heating water for their tea.
It is almost impossible (at least with the technology at the time) to completely destroy built-up defensive positions and kill all defenders. In WW1 they would have insane barrages by thousands of artillery pieces firing continuously for half a day before an attack, and the positions would still be heavily and effectively defended.