I use some fake plants in my enclosures -- in the glass-fronted PVC tanks more for looks than anything (hide the water bowl from my view, etc), and in tubs just for a tiny bit of enrichment.

Most captive snakes are expected to drink water from a bowl rather than droplets on surfaces, and most snake enclosures hold the appropriate amount of moisture without depending on plant transpiration, so real plants are in many cases simply an avoidable complication for snakes. For other taxa (arboreal geckos and frogs) it is an entirely different situation.