Dee, have the critics actually provided any reasons?
I'm looking at it on my laptop, which is calibrated.
My preference for an image like this would be to present it in a 'natural' fashion. Your treatment looks over saturated to me. The reds and greens are blown where I would have expected to see tonal variations as would occur in nature.
Overall, the image also looks to be over-sharpened and a bit too bright.
That said the image is striking.. if that was what you wanted to achieve.....?
As we know nothing about either your friends or the critics, we can only guess as to why your friends like the images and the critics do not.
If your friends are not photographers, they will see the bright and unusual colours and they will probably think that you have preformed digital magic to get the leaves looking the way they do. They likely have little or no knowledge about composition and post-processing work.
Experienced photographers (and I assume the critics you have mentioned, likely fall into this category) like seeing images that are well composed and are processed in a way that brings out the beauty and subtlety of the subject. This type of post-processing work requires a lot of finesse and skill.
Dee, I concur wholeheartedly with Manfred's comments. I have never taken pictures of leaves, on the ground or on trees. I do not think I have the skills to do it well enough. That is: bringing out the beauty of the leaves. That is only my opinion though.
Cheers Ole
Olympus calls this style POP Art, you can either process the RAW capture to give this look or use the camera's Art filter to capture in jpeg. I use the filter for specific scenes, your autumn leaves would be a good subject. Nicely rendered subject.