Complimenting.... a Conundrum.
Here's my thing, though I have had some compliments on past builds, I also know that they were not that great, and, that I am still in the learning process, and getting better, as I am always pushing myself to do better, and also becoming my own worst critic, while I agree with Constructive Criticism, I also see that a few positive comments are not going to hurt anyone as there are so many Excellent builders out here that Spur and Inspire, even me, to immitate or work up to an Excellent build. Now I can not speak for any and all that are beginners or just starting out again. But I know what I do, and I know what I want to do...... and it is to "Improve". So long as a Builder understands this, no one is in danger of continuing crappy builds.
Per the forum, Negative feedback on a build is going to hurt the ego, and words can be missinterpreted, which is why I support Constructive Criticism, at least you can tell someone what you see wrong, and tell them how to improve it, this can be a type of positive reenforcement without complimenting on something that looks bad.