I agree with you. But i think that beyond scale and state of mind, one key factor in B2B is the tolerance of the organisation (not only the leader) to change and experiments.
It takes a great deal of leadership to bring everyone on board and convince the naysayers.
In my case, on of my customer has ~100 users. the problem is not my stakeholder, but a slice of the 99 other users, who have to deal with the change. Some request additional training, some complain...
With all the good will of the leader, i just fear that he eventually grows tired of fighting for each change, regardless the value brought by such change.
So the question about experiment is maybe more a question of overcoming user resistance (and, in a company, the associated cost).
The reactions to UI changes in Facebook are probably a good indicator that it's a tough battle :)