We can probably agree to disagree. If all I had was sub 15kn winds 99% of days, I would give up my TT and take up foiling. If it was less than 10kn, I wouldn't kite at all.
Actually, that's a lie. I would move.
I'm not saying foils are bad. I actually love them for the amazingly smooth power delivery and glide. But assuming you're learning in the water, newbies have a tendency to crash their kites. A lot. Can you learn on a foil? Of course. But LEIs are much more forgiving and easier to learn on the water. If I had to learn on a foil kite, I would've given up after the 3rd long swim back to the beach.