Usually the folks with a better lock do not get hit. The thieves are looking for the easiest targets and won't waste time on a tougher rig to break in. Both deadbolts on my Class C door are always engaged and the cab doors are locked and the alarm on anytime we are not present.
Additionally I have a smallish safe that is through bolted and any items of value not on my person are secured there. Could someone get it out.... perhaps but it will take more time and tools than most of these pieces of garbage have to spend.
Don't be the soft target... IMHO:
If you make it easier to rip someone else off you have done about all you can do but caving in to the low life's by letting them dictate your behavior {taking any/everything of value out of your rig every time}... is simply enabling/encouraging that sort of behavior.
As always.... Opinions and YMMV.
:C