If I have a horse and plow and you show up with a tractor, I will no doubt get a tractor asap. But if you show up with novel amphetamines for you and your horse and scream "Look how productive I am! We'll figure out the long-term downsides, don't you worry! Just more amphetamines probably!", I'm happy to be a late adopter.
A tractor based on a Model T wouldn't have been very compelling either at the time. Not many horse-drawn plows these days though.