I understand not finding the new art direction appealing, especially because the old designs have been implanted in a lot of people's minds. However, I feel like the backlash is way too extreme, especially since the characters are still recognizable. They simply exaggerated the designs to be more cartoonish while respecting the original style (the characters are still grungy and keep the basic elements of their designs).
Look, it sucks that we didn't get the Last Wish style, but I'm at least happy that DreamWorks is still trying to bring new visual life into this series.