The shape of the pitch plane flight envelope is due to the different design gust loads at
Vb & Vne. The airframe should be capable of withstanding the limit load at any speed but the fact that it will be able to withstand higher loads at slower speeds is rarely placarded. The K21 is one exception.
Modern gliders are very slippery; one certification standard is that the glider should not exceed Vne in a 30 degree dive with the airbrakes extended. In a steep nose down attitude with the airbrakes in, the only way to stop the glider whistling past Vne in a few seconds is to load the wings - high AoA=lots of induced drag & helpfully pulls the glider out of the dive.
Pulling 130% of the limit load will damage the wings, but at least the wings should stay attached. Fly at 130% of Vne & there's no guarantee that the elevator will stay on. In a steep nose down attitude a slick glider will shoot way past 130% Vne
unless you pull some g.
The utility category minimum limit load for sailplanes is 5.3g, add in the inherent slipperyness of modern gliders & you can see how glider pilots are more concerned with Vne than pulling too much g. In practice, nobody pulls anywhere near 5g in spin recoveries but hesitant students sometimes get uncomfortably close to the redline. The de-brief may include the "excess g is safer than excess speed" line just to encourage them to pull more than 1.1 g in the recovery.