My only real issue with it is the actual pacing of the season, and the splitting of the season in half didn't help matters. Breaking Bad had marvellously excelled in creating a slow yet extremely compelling build up to moments of intense significance, and while the pace was always quite rapid in terms of how things actually progressed, on a week-to-week basis, the show felt to be of a relatively measured pace. In both parts of the fifth season, this really wasn't possible, and at times it resulted in the events feeling rather rushed, and occasionally unearned (so I'm in complete opposition to your view that you could watch Blood Money and skip to Ozymandias/To'Hajilee without missing anything important).
Overall, I still thought it was rather fantastic, the second half in particular (although I didn't really like the final, I thought Granite State would have worked much better as an ending), and thought using the Neo-Nazis as Walter's accomplices was an inspired choice (it wasn't the final hoop he had to overcome, it was a removal of the glamorisation of the previous working situation, a substantial contrast to the working environment of Gus and highlighted Walter's completely chaotic reign [as he was now directly down in the gutter of the drug trade, despite his previous unwillingness to do this], and emphasised his complete and utter delusional state about his own intelligence, power, and ability to minimise the fallout).
The reason it's not criticised more? Well, I think this thread and the overall critical response to the fifth season says it all, it's not criticised more because there is a heavy belief that it was an excellent fifth season.