Scribbler397
a.k.a. Tree Hugger
How many pwps does one need in order to have a perfect town?
I don't have a trash can. Are there any other projects that bring down your score?
I think you need more of the "abundant nature" type of PWPs. Here's a blog post explaining how the town rating works: http://bidoofcrossing.tumblr.com/post/44114461860/great-blog-glad-you-still-have-it-would-you-happen
One thing, though, is that the "underdeveloped" title doesn't necessarily mean you don't have enough PWPs, as people popularly believe. Some things to consider: how many villagers are currently living in your town? Do you have a few of the "main" PWPs (Club LOL, Dream Suite, Cafe, etc.)? Do you have enough trees and flowers?
If you don't want any abundant nature PWPs (or your villagers haven't yet suggested any), you could make up for it by planting more trees and flowers. I didn't have even 10 PWPs when I got perfect town, but almost all of my chosen public works were of the "abundant living" type, and I had planted a TON of trees and flowers. Villagers love foliage!