I, too, used to harbor the same prejudice. Now I have a plastic recorder (that cost me next to nothing). I like the way it sounds, but not its right-handed setup. I also have a Dixon DX026, which is plastic, and I like its sound, too. Quality plastic whistles are terrific, in my opinion!
I’ve never played one. Someday I intend to, but right now I can’t give a fine wood instrument the care it deserves.
I have a few plastic whistles, & most sound mellow, but louder, than your average recorder, but a couple sound similar to a regular whistle.
I, personally, think that delrin sounds very close to wooden, so will never buy a wooden flute/whistle, & so I will never have to worry about its care.
Delrin is much easier to care for.
I went with the suggestion of a Waltons Mellow D. It’s got a nice sound for a cheap whistle, and as the basis for the Freeman Mellow Dog that is hopefully coming my way eventually, it makes sense to me to learn on a similar instrument. I also added the Monster Grips recommended in another thread (https://forums.chiffandfipple.com/t/mcgoldrick-mcsherry-new-album/91/1) as thumb pads, and it has made my grip much more solid, especially on the C#.
I also did the blue-tack tweak, which has helped with the airflow, especially stability in the higher notes. While it’s not my dream whistle, it’s not bad. I am squeaking and skronking more and more rarely.