I find myself disappointed that it doesn't have either pontoons or helicopter blades as well.
Most RRVs (Road Rail Vehicles) are modified by third party specialists, you buy the exact type of machine you wanted (maybe it's a custom thing to put up fencing for example) as a road vehicle and then a specialist with know-how and welding gear sets about turning it into an RRV. This way the company making a digger or whatever doesn't need to know the arcane elements of railway safety regulations, and the company doing the modifications doesn't start making a dozen road-rail tipper trucks only to find that now everybody wants to buy cranes instead...
I have no doubt whatsoever that such a business would accept a sensible proposal to add pontoons or helicopter blades, at least if you offered cash up front - but unlike RRVs there's no immediately obvious reason to build such a thing.
"no immediately obvious reason to build such a thing."
To the contrary, every supervillain should have at least a few air/sea/land backhoes. With lasers. How else are you going to build an addition onto your lair?
"With my fleet of air/land/sea backhoes I shall destroy the interwebs! Mwhahaha!"
It's not a backhoe!
Indeed, it even says it's precisely a 445E right there on the machine itself.
But I think to a certain type of person any plant they can't immediately classify is a "backhoe" in the same way that a friend of mine cheerfully classifies any wildlife larger than a squirrel as "bears" (vicious wild animals were in fact eliminated from this island so that today the worst you're likely to experience is being trampled by cows or bitten by someone's pet dog).
All this can be yours for $45,000.
The backhoe is a metaphor.