Quite possible but most likely complacent. The last serious attempt on the president was over 30 years ago.
2) so PC-ized that they were ineffective or
Pierson got her job because she was a woman, there is no doubt about that. But you also have to remember what prompted her appointment. It was right after that scandal about the Secret Service Agents drinking and whoring down in Venezuela. A shakeup was definitely needed after that and I'm sure someone thought that a woman would be more believable when the agency claimed it was going to cut out the skit-chasing. Unfortunately the woman they chose was not up to the job.
3) the agents themselves really didn't care what happens to Zero
Then they need to be tracked down and fired. Immediately. This isn't a job where you get to choose to defend who you like. The agents are there to protect the President and his family regardless of who they are, regardless of how they treat the agents on the detail, and regardless of their personal feelings. If they can't do that then they have no business being in the job.
I heard that once Gonzalez got inside the White House, the Secret Service agent at the door tried to stop him but it was a small woman and he overpowered her. So political correctness could have had fatal consequences if the off-duty agent had not come along at the right moment to tackle Gonzalez.