Earlier quoted context omitted.
My suspicions are that he wanted to put the readers into a position where we have to figure out what we actually think is true, and what we think about the arguments themselves. I guess what I want to say here is that making himself clear, in the sense of stating propositions, is not obviously the goal of Plato. You are coming at this all wrong. The important question is not what Plato did and was trying to do, it is…
What if Plato thought that (at least part of) the truth was that it was more beneficial for people to think and seek than to be told the pre-canned truth? Then getting people to actually read and think about Plato (or other Plato-ish philosophers) would be more valuable than to "present Plato's ideas to the world as an organized philosophical work". > Also, for one particular topic, namely biology, do you agree that…
No, what happens through this process is the student gets an idea in their head and thinks it is correct. The only way to check it out is for the student to state it in a prepositional form to some other smart philosophers and see if they punch any holes in it. But I guess you don't want them to do that because you sense, I would say that correctly, that many Plato's ideas couldn't stand up to that sort of critical scrutiny.
By the way, I do think Plato's dialogues are well-worth reading, it's just that I think many of his ideas were mistaken.