"My confusion is on why so many people in the prediction page select 30 -40 numbers and play those same numbers for every state pk 3/ day4 drawing on any given day."
It doesn't cost anything to predict in one state or in all so they are just seeing how the same numbers will do in other states. Statistics are shown and it's easy to evaluate anyone using the prediction pages. Some who use the Pick 3 Forum will predict 30 - 40 numbers and say something like "good for all states" where it's very difficult to evaluate their results.
On your first visit it looks like you noticed that playing 30 to 40 numbers in just one state means playing at a loss and playing in many states where it's logistically impossible would be a huge loss. Maybe it's done just for bragging rights because there is always at least one reader congratulating them. Some of the Pick 3 state specific threads have posters who give statistical reasons why their numbers have a better chance and might be what you're looking for.