I understand it's walking distance to two parks. The walk between Epcot and YC/BC is about the same distance as the one between MK and the Contemporary (a walk which hasn't been mentioned much on this thread, but about which many people complain when denied monorail access: 'too far'; 'what if it rains'; 'difficult for little kids and old people').
I thought that, too, but I think the Contemporary isn't being mentioned much because the OP was concerned about the Poly... not like the OP is even reading this anymore.
Which is annoying because I post threads with legitimate questions that no one responds to.... someone posts a rant thread and everyone responds. Perhaps I should begin to make angry thread titles to entice people to read...
On the other hand, it's about 15-25 minutes to DHS. Yes, I know there are Friendship boats. They seem to work great between the two parks, including stops at the three resort groups. But, bluntly, those same boats seem not to be good enough for the guests at the Polynesian. I have no idea how the GF guests feel. I haven't seen any complaints from any.
Actually, they aren't the same boats. The Friendship boats are FREAKING SLOW, and I always manage to beat them on foot. I would much rather ride the boats to/from the Poly. However, I wasn't arguing my case, just trying to validate other people's decisions, as not to be a "AESOP."
Not to mention, you have to enter Epcot through International Gateway, and World Showcase doesn't open until 11:00 AM most days, so it's about a 15 minute walk to the front of the park, as well.
And not everybody who's changing resorts is moving to an Epcot-area resort.
Who said they were?

It's a common suggestion because if someone is looking for convenience to the parks, they are a good option. However, if someone was dead-set on the monorail and is now just looking to save money, obviously the values or the moderates would probably be a better fit.
Now that all of your questions are answered...
Someone. Please. Kill. This. Thread.