you simply have to accept that a zombie movie by definition isn't going to exhibit high levels of logic and reality
You might think that, but in all honesty it seems a fairly substantial amount of people don't exhibit a high level or logic in crisis or high-stress situations. Hell, it's winter - hardly a crisis - here and based on the way some people drive you'd think it was summer on the Autobann: speeding, passing across solid yellow, passing at high-speed in the slow lane, passing at high speed off the curb, etc. It's nuts.
Have a look at how people act on Black Friday in order to score $25 off a POS television. Look at the people buying food with stamps and chatting on the newest iPhone.
Assuming logical and rational thinking from a large portion of the human populace is going to be a losing proposal. In fact, the best way to survive may be to assume that the majority of people are going to descend into a dumb panic and make terrible decisions that could get you - or them - killed.