Where did I say that, and where did I say that digital wasn't good only because of bad habits? Stop putting words in my mouth, Benedict. This parade of strawmen you are pulling out is getting annoying.
Digital isn't a good first medium because of a myriad things, the first of them being layers upon layers of indirection between the artist and the work - the tablet, the display, the software's intricacies and quirks, etc. Sketching on the tablet is significantly harder than on paper, and a lot of digital artists resort to techniques which have more in common to collage than painting, with use of masks, photos, undo feature and adjusting the stroke shape with an eraser. This is not going to train the hand-eye coordination to any real degree. You need a more hands-on medium to do it. I would try digital only after getting a solid background with something else. (And I experimented with it BEFORE I even studied systematically. Ever heard of Dr.Halo II? Deluxe Paint? And after - remember Fauve Matisse? I eventually switched back to pencil because digital was way too mushy, only painting over scanned pencil or ink drawings. Only then, and only after switching to structural drawing, I got some real progress.)
The best first medium is actually graphite pencil. It is the most hand-on one, it is quick, it is extremely cheap, can last you through all of the fundamentals except color, and a good skill in tonal graphite drawing will translate into tonal painting readily.