Apologies if I upset anyone. I didn't mean to. My own view is that people can play whatever they like, so I guess that people holding the opposite view must be the ones who like to dictate what other people play.
To expand my point I can quite understand that people who like lines preferring or needing lines. I can also understand that people who can play unlined might be quite happy without, but I can't see why the presence of lines would be a problem to them. i.e., as per my first post, a lined one has all the options covered. Therefore for a first timer I'd have thought lined would be best.
Aesthetics is a different question of course. I quite like the look of fretted basses, and an unlined fretless just looks a bit uninteresting to me, but can perfectly understand that other people prefer the unlined look.