I agree with Chris's post entirely.
A lot of times snake owners would love to say "Oh look my BP is sitting still on me, he MUST love being held and love me!" When in reality they are just attaching their own emotions to a snake that has no emotions as we do and was trying to get warm or hide (not moving is a defense mechanisim sometimes!)
Again I agree with Chris mentioning TOLERATE. There is a huge differance between "oh my snake loves handling" and a snake tolerating handling. If snakes were emotional and needed human companionship I believe they would seek it out and show behaviours that agree with this in the wild. But most snakes do not even enjoy spending time with their own species, let alone people. Snakes had NO reason to develop emotions the way humans have them. They need to eat, drink, breed and sleep. Period. Emotions and relationships are not developed in animals when they would get in the way. Snakes are killers, hunters and breeders to propogate their species, but most are solitary.
Do I think its important to handle them? No. We hold a couple of our snakes because they are favorites and WE enjoy handling them, they do tolerate us well. But a few of my snakes get handled less, like maybe twice per month during cleaning. It doens't affect them either way, and they aren't dying of lonely broken hearts because they would prefer me to leave them alone in the first place.
The only other reason I can see to handle other than human enjoyment is that sometimes exercise in gravid female corns helps out a lot I have heard with avoiding egg binding. But we have a large exercise cage for this.