Well, that advice from the election kind of assumes one's parents could actually lend their kid 20 grand. If he just said, try to start your own business, that would have been great advice, instead it came off as out of touch.
One thing to take into account in WW2 with the soviet union is they had a nonaggression pact with hitler, and had actually collaborated against Poland. It was entirely conceivable that the allies might end up fighting both the soviets and the nazis. To that effect, we assisted Finland against the soviets early on, which kind of throws out Snailmans idea that Roosevelt had any love of the soviets. Also, regarding the profiting aspect of war, Roosevelt outright said he didn't want anyone to get rich from the war.
A whole other angle is the R&D aspect and technological advances made. At the start of the war, the Japanese and Germans had serious advantages, it was probably inconceivable that the allies could catch up and pass them as they did. The Zero outclassed anything we had in speed, maneuverability and firepower. We practically had no tanks at the start either and the Germans had a huge advantage there over all the allies.