are too simplistic to maintain interest 
(ROOT (VP (VBP are) (ADJP (RB too) (JJ simplistic) (S (VP (TO to) (VP (VB maintain) (NP (NN interest))))))))
(ROOT (VP (VBP ) (ADJP (RB ) (JJ ) (S (VP (TO ) (VP (VB ) (NP (NN ))))))))