is one reason it 's so lackluster . 
(ROOT (S (VP (VBZ is) (NP (NP (CD one) (NN reason)) (SBAR (S (NP (PRP it)) (VP (VBZ 's) (ADJP (RB so) (JJ lackluster))))))) (. .)))
(ROOT (S (VP (VBZ ) (NP (NP (CD ) (NN )) (SBAR (S (NP (PRP )) (VP (VBZ ) (ADJP (RB ) (JJ ))))))) (. )))