I try to chain and lock my saws together inside the truck. A lot harder to pry-grab-dash, when you're trying to pull a bunch of saws through a tool box door that is big enough for the big saw, barely. Pulling 6 saws out of the tailgate from the front end of the bed would be a chore, even. 
If regularly using a cargo platform, I'd definitely have a cable or chain running through everything and the frame, and cover it up. No need to advertise. 
A very lightweight plywood box, finished neatly, on a cargo rack could look good and hide valuables. 
Tweekers will siphon gas. 
My cargo platform is useful, occasionally, especially if I want to run to town to fuel up. I don't have space in the truck for a half-dozen gas cans. I can easily make the run to the gas station in any vehicle. Cheap, too, for the usefulness.