I believe that plants respond to people. They can tell by the way you handle them whether you love them or not. Hence the term green thumb, you either get on with plants or you don't.
They are living things with the capability to evolve just like us. To my mind anything that evolves has sentience.
If you look at your plants as being just a smoke at the end, they will pick up on this, think fuck you, and give you a shitty, foul-tasting yield. Your plants need to know that you are going to look after them, carry on the best of it's genes into bigger and better harvests.
Love your plants, respond to their needs, and you will be rewarded.