You have a point, as plastic canvas can be 14hpi and stitched like cross-stitch, or 10hpi/7hpi and stitched like tapestry. Then again, tapestry canvases can be stitched with floss and cross-stitch instead of wool and tapestry stitch. Where to draw the line?
But I think we're all agreed that these should all come under a Needlework heading (or similar), rather than divided across the general Crafts & Sewing? At the moment, everything seems to be going into the Needlepoint category.