That's not true - one of the proposed use cases for these tyres is airplane landing wheels which are typically designed to work at up to 235mph. Aircraft engineers have to make major compromises to make sure they can land safely with a flat tire and when they get it wrong it ends really really badly. The concord crash, for example, was caused by a flat tire. Pieces of rubber from the flat tire flew up and punched a hole into a fuel tank. The jet fuel was on fire as it poured out of the rank creating a horrific fireball and the loss of fuel pressure caused two engine failures.

113 people died and the concord was declared unsafe since there wasn't any (affordable) way to redesign the aircraft to handle a flat tyre.

Sure - the wheels they use on the rover can't handle those speeds, but it could easily be modified to work. The bicycle tyre they demonstrated is a better example. It has a rubber coating which will heat up and provide plenty of traction if properly designed.

The real issue is weight. These tires would be too heavy.