I can understand why the industry mounts the pump inside the fuel tank. In the old days, the fuel pump was mechanical & mounted to the side of the engine. They had an arm that worked like an old water well in a forest preserve park. The arm would be pushed down from a cam inside the engine. When the pump started to fail, you had gas all over the engine compartment.
Inside the tank, if it's leaking, it leaks into the perfect place such that nobody knows about it. Unfortunately tank pumps are terrible to replace when there is no easy access. For most vehicles with fuel tanks under the truck floor, it would be real nice if there was an access panel under the removable carpet. But maybe there are liability issues with Ford Pinto like concerns.