>>24505695 (OP)
Plato doesn't hate poetry at all. He has reservations about it (two examples outside the Republic: 1) in the Apology, the lack of understanding that poets contemporary to Socrates had in what they were doing, 2) in the Euthyphro, the tendency to take the myths the poets wrote about as simply true), but the Phaedrus' big central myth is a palinode in the manner of Stesichorus, in the Symposium poetry is held up in the Diotima speech as one of two examples by which mortals may achieve qualified immortality, and even in the midst of the critiques of poetry in the Republic, it's said frequently how beautiful the works of the poets like Homer are. And let's not forget that the Republic readily uses works of poetry to develop its contents--the comedies of Aristophanes (the Birds is a model for developing a new radical city, the Frogs informs the discussions of poetry, the Assemblywomen is used for the first two of the "three waves"), Hesiod's Works & Days (for the noble lie about metal souls and the devolution of regimes), and Sophocles (the tyrant in books 8 & 9 is Sophocles' Oedipus). Now, the critiques of poetry in the Republic surely seem harsh, but they don't stand simply, since *Eros* is also critiqued in the Republic and Eros is treated in the Symposium and Phaedrus as the philosophical passion par excellence.
As for the difference in literary styles between Plato and Aristotle, that's also up for contention, since Aristotle also wrote dialogues that were appreciated in antiquity, but which we only have access to via some quotations, paraphrases, and summaries. The works we have by Aristotle seem to be works meant for within his school, and it may be the case that Aristotle thought it was important to reach his more skilled students by putting the more frank work of his activities before them. Plato was writing in light of Socrates' death, and may have felt it was important to justify philosophy to those who could read in order to secure the activity for future generations. But then, compare something like the Phaedrus with the Parmenides, Theaetetus, Sophist, Statesman, and Philebus, which come across as his most technical and difficult writings.