Sentence:  D[ryden]'s lit[erary] patriotism [is] genuine, but he made good use of it to cover up the “<WSD>bittiness</WSD>” of his own plays. He could always point to the “<WSD>bittiness</WSD>” of Shakespeare and does not realize that though Shakespeare wrote tragi-comedies and indulged in double plots, he nevertheless attained an unity of his own, an unity that is missed in e.g. "The Spanish Fryar". 
Meaning of the word marked with <WSD> tags:  The quality of being bitty; fragmentedness.