What is so hard about flying through Class C or D airspace? It may not have been an instant passage but it would no doubt have eventuated in to one. Or why could they not come in and land and have a breather and get their ducks lined up again?
I’d hazard a guess (seems to be a lot of them being thrown around in here already), that they were not confident in dealing with the airspace. Whether that was training, exposure or currency related who knows but perhaps there lies the answer.
Is the airspace perfect? Probably not. But it is not an impossible space to pass through. They did not have to continue.