I have to comment on what so many are saying:
Small windrange, and bad upwind.
Upwind is never a problem on a hydrofoil, and these kites are not really meant for anything else IMO, apart from snow.
Also, in winds where big sizes are used say 5-7 knots, the wind is usually extremely stable (sea breeze winds in many places) so you dont need range, and also I believe all kiters will rig down if wind should pick up.
Here the advantage of a non-air-filled single skin is great, you can just land the kite and pack it down immediately, not waste time on pressing air out.
Big lulls can be a more common thing in superlight winds - and here these kites excel.
Strutless LEI kites have a bit of the same characteristics regarding windrange, great low end and hangs in less than rideable, but small range.
Thus I understand why there are many who like the bigger single skin kites.
Of course, for non-hydrofoils or for jumping, they are not the thing to choose.
My main point though, is that the windrange and upwind is not an issue for most hydrofoil riders, with a big single skin kite, so would never be my reason for not choosing such one.
Too low peak power could be my reason though - but the low price on most, and superfast and small packing, is of course appealing.