One point not reiterated yet here -- the atmosphere down low is very
different from what you're used to at 2000 feet and above. It's easy
to say "I haven't unintentionally stalled /spun in a thermal in a
thousand hours. How much of a dope do you have to be?"

A short list of what's different down low: The atmosphere is much more
turbulent. Thermals, such as they are are much smaller. In this layer,
many small punchy thermals will start. Many will die. The ones we use
up higher consist of many little parcels of hot air that have
coalesced. Most thermals are either short lived, or basically
unworkable to a modern glider. You're in the boundary layer where wind
is being affected by the ground, so there is wind-induced turbulence.
Punches of strong lift/gust followed by sink when you make a half turn
will be the norm.

The ground picture will be totally different to the pilot. If you turn
downwind at altitude, you don't notice that much. If you turn downwind
at 300 feet, all of a sudden the ground will rush by and, this being a
high stress moment, you may pull back. Just as the gust you turned in
fades, or the thermal turns to sink. And when the canopy fills with
trees going by at 70 mph, the urge to pull back will be really strong.
You may push forward to recover at altitude, but it's really really
hard to do with the ground coming up fast.

So, just because you've never unintentionally spun at altitude does
not mean your chances at 300 feet are the same.

Not to raise a tired subject, but why we give out contest points for
thermaling at 300 feet or below remains a puzzling question to me.

John Cochrane