The issues I had with LFODH had little to do with the brainlessness of the general plot line or characters. Pretty much every action movie suffers from those issues.
The three main issues I had with it were:
1) Geographical inaccuracies: You ever drive from DC to WV? It's not a quick trip.
2) Wherever there is gridlock or stalled traffic, somehow John finds a clear lane, whether in the tunnel sequence or getting out of town.
3) In general,
more continuity errors than any movie I have ever seen. It's like they didn't even try.