I don't like praising people just so. I've seen it too often to consider it meaningful. Alex is doing his job and I paid him and I continue to be engaged. If I didn't care, I wouldn't be here.
I get what you're saying but there are also people being paid for their work for an average performance, or even worse. I feel positive reinforcement is suitable for those who excel at their work, regardless of the amount of money they're getting for it. Of course too much praising and then you slowly lose meaning and it just becomes bland. But in the end it doesn't hurt anyone, especially the devs who are always glad to hear stuff like this.
+1 for the communication part, there wasn't a dev in my whole life who responded to almost all of my questions and suggestions, let alone with added explanation and thought put into answers.