Because it definitely doesn't have a submarine mode.
Thanks to the massive Hellcat engine under the hood of the Ram 1500 TRX, most people who get a chance to drive one tend to use it for drag racing rather than its true purpose. In fact, we see drag races featuring the TRX more than we see any sort of off-roading testing, from one against a Camaro ZL1 to another against a tuned Silverado. These are all ridiculous considering that the TRX is supposed to be something of a Baja bruiser. But after seeing the below post from Xtreme Off-Road Park in Texas, maybe TRX drivers ought to stick to the blacktop.
It's unclear exactly what happened here - all the info we have is contained in the above images - but it seems that the driver was trying to ford a body of water that commenters on Facebook say is roughly 31 inches deep. It could be that the driver panicked once water started entering the cabin of his $90k truck and floored it, only for all four wheels to dig deeper. Another possibility is that water got into the intake system somehow, or perhaps the driver was simply too inexperienced at this park to know which angle to take. Whatever the cause, this looks like a terrible thing to happen.
Sadly, this isn't the first time we've seen these immensely capable trucks get driven by those who have a little too much faith in it's abilities. The Ford F-150 Raptor is another vehicle with advanced off-road suspension and a beefy engine, and some owners think that this means the truck will happily perform insane jumps with no consequences, only for them to learn that the opposite is true. While the Ram TRX is undoubtedly a formidable weapon in the right hands, here it seems that whoever was driving should have rather just stuck with mountain biking. At least those vehicles can get wet and keep working.