Reasons for prepping: I've come to realise how fragile our economy and infrastructure is, and I've got to safeguard my families future incase something does happen. Id rather have the preps and not need them, than need them and not have them (I'm sure that reasoning would be echoed throughout the forums)
Other reasons you just need to look out of the window and see how bad things are descending into madness. People fighting wars, freaky adverse weather conditions (I've lost track how many floods, heavy snow storms, forest fires that there's been this year) Take your pick.