Yes, it IS hard, when you are new, and using your normal tubekites.
When experienced, no problems riding in 10 knots with tubes between 8 and 12 m2.
Disagree you need to keep foiling, or avoid crashes in transitions, doesnt mean a thing when experienced, you can easily keep the kite alive as long a you know what your kite is doing, no problems
The thing is, when you have just learned to foil a tad only, you WILL drop the kite too often, and most often not possible to relaunch, at least not easy in 10 knots which is even less at the surface, so yes, it IS hard.
Then you can get lighter kites, one or no strut, which makes it easier yes, and actually needed in sub 10 knots.
But you can ride in lulls with normal tube kites also, when you know how to.
12 knots is where it gets very easy to keep the kite alive, if a normal tubekite, even for the beginners who can ride a bit.
I recommend around 14 knots for the very beginner, in order to learn hydrofoiling, 12 knots is too low for the very first times.
So what you see is correct, many will drop their kites and suffer in 10 knots, and others will ride effortlessly, even with the very same kites and gear
I think many answering here only speak for themselves, and not for those who are fairly new