If you can't finish a WOD with good form, you need to scale somewhere. Any coach worth his salt should be saying something similar.
Any fitness coach worth his salt will tell you to stay the fuck away from crossfit.
Here's a fun fact: most of the competitive crossfitters don't actually do crossfit as their normal workout. They train for a month or so to do the crossfit routine but the rest of the year they do a more traditional strength and cardio regimen because those regimens are more effective and efficient than crossfit.
Think about what crossfit is at it's core...a bunch of exercises designed to use weights and body-weight (often with poor form) to get your heartrate as high as possible for a short duration. It's basically using weights to do HIIT and pretend to build strength at the same time. There are better and safer ways to get your heart pounding and you don't need to do it by clean and pressing 2 plates 30 times as fast as possible while straining your lower back because the weight is too heavy or you're too fatigued, and there are better ways at getting better at pullups than tying resistance bands to the pullup bar while doing weighted pullups. Yes, that's a real crossfit exercise and no, it doesn't make a bit of sense.
Not to mention the exhorbitant fees it costs to even go to a crossfit gym, er 'box.'
If you want to build strength, there are a ton of proven weight training routines out there to do it. If you want to build cardio capacity, get on a good running program. Because when you PT in the military, regardless of service, you're going to be running. If you want to do both, then build both aspects into your workout regimen. You won't die from running a few miles before (or after) lifting weights.
Crossfit would be effective if done as part of an
advanced routine once someone has mastered form the point where they know to put the weight down instead of blow out their backs attempting to finish a WoD by any means possible. But that's not who Crossfit panders to. The fact that any Joe can walk into a 'box' on day one and get put on this type of routine on day one without having lifted a single weight makes it dangerous, even after all the mandatory classes.