Pelican cases certainly have their uses (i.e. to protect delicate and expensive pieces of equipment). But once you get outside those uses, they are expensive, far too bulky, and generally less useful than the alternatives. Unless you are locking up your tools on your roofrack, why wouldn't you just use a tacklebox/actionpacker/or even a cardboard box???
When you consider the outside dimensions of a pelican case versus the interior capacity, the weight of an empty Pelican, and the cost, why would you consider it unless you get them for free and have no other solution.
To spend $100 on a pelican case to hold wrenches and tow straps that will sit inside a vehicle sounds like a waste of money, space and weight.
Now, when you need to store your micrometers, fiber splicers, and dilythium crystals inside your truck - I understand the need/cost for the pelicans.