Isn't unconditional praise empty praise? Is getting a trophy at "Everyone Gets A Trophy Day" meaningful?

No, but unconditional praise is not the same as unconditional love. (The latter seems to be closer to what PJ was talking about as parental pride, if I'm reading him correctly.) They are too often confused. Unconditional love is important, but unconditional praise is harmful, as is conditional praise that is predictable enough that the child learns to anticipate it and act based on it, praise that is given like a reward (a "status pellet") rather than as a genuine expression of gratitude or impressedness. Alfie Kohn has written a lot of interesting things on this and related subjects.