Never stretched until i found it felt like my hamstrings were continuously tight a few years ago. It may not have been cycling related, i'd never suffered before. I did stretch a little, for a few weeks. Didnt seem to make any immediate difference to the tightness in my legs, then, as with many things i forgot about it, the stiffness went.
3 years later, i do longer rides albeit not pushing myself so hard...and reading this topic reminds me...i don't have that stiffness any more. Certainly dont stretch any more.
As mentioned in an earlier reply, i do sometimes get out of the saddle and stretch my back, legs and neck. But this is only once or twice for a minute in a 3 or 4 hour ride. Its not to prevent tightening up, more to alleviate some immediate stiffness.
