I invite a food scientist or some such type to correct me (it's HN, so there's probably one lurking around somewhere), but the margarine issue was due to high concentrations of trans-fats coupled with the already high concentrations of saturated fat.

I believe a number of the "vegan" butters on market shelves today strive to avoid this issue, hence it's not necessarily the same... or, rather, to put it another way: just because something was done wrong once doesn't mean it can't be tried again with a better formula.

It's not like regular butter is being phased out here, and people really shouldn't be consuming so much of this stuff (butter or vegan butter) period.