First, I LOVE Moviestorm, but as I do various projects I keep getting one piece of feedback over and over again. People don't like the look.
I am not sure how much of this is 'uncanny valley' in Moviestorm and how much is just lack of familiarity with machinima in general.
One thing to look at also is who is making the comments. If you're on YouTube, then most likely these are coming form those who think machinima should only be done using games like Halo, Mech Warrior and Doom.
Those of us who started in The Movies got many of the same responses when we started posting our films. Once we started being more creative with camera angles, creative editing, color correction and adjustment using outside editors and other effects, the comments got a lot better.
As was mentioned in another post, not showing the whole movement (arm raise to finger point) by either having the camera elsewhere and then cutting to the character or focus on a facial response/expression, then cut the camera to another body part can overcome some of the sluggishness (wooden feeling) of Moviestorm. I saw one film where 2 characters had to tgrun around and then walk. Instead of moving the camera angles or using cuts, the director left the camera showing the whole body, including the feet, from the start of the turn to the walking. Made the scene almost unwatchable. If they had started the camera on maybe the head and then either moved the camera to a different angle while the turn was made or just cut the camera during the turn and cut back in after the turn with a slightly different angle, the scene would have improved and the comments about looking like crap would not have been posted.
The main thing is, you have to be able to work with the limitations and get creative. There will always be those who won't accept MS so don't put too much stock in some of the comments.