I have argued with @pfdietz about this before. In the zeal to make the point the majority of leading edge heating arises from the dissipative effects of shocks, they make statements that have to be very carefully parsed to be correct.

You are right. Isentropic compression will result in a higher temperature of the compressed fluid. This is undergraduate gasdynamics. In these supersonic flowfields with high shock strength though, the shock acts as a very dissipative compression mechanism. Behind the shock is a compressed fluid that is much hotter than it would be if compressed to the same pressure isentropically. Shocks are dissipative, like friction, but shocks and friction are not the same thing.

So unless you remove heat from a perfect compressible fluid being compressed (i.e., via a non-adiabatic process), it will always be hotter post-compression. It's just that the compression and heating that shocks effect causes much greater heating than the isentropic case.

In what we call "acreage" where the forward-facing area is limited (e.g., upper surfaces of wings and vehicle bodies), other effects, including turbulent skin friction heating, can dominate the local heating rate.

Thanks for the explanation. My undergraduate fluid mechanics class did get into shock waves, but not the temperature implications of them.

That paper doesn't appear to have much to do with what we're talking about here. The transfer of heat to the vehicle from the hot shocked gas is another issue entirely.

Anyway, it's foundational supersonic fluid physics that shocks create entropy.

"Shocks are irreversible occurrences in supersonic flows (i.e. the entropy increases)." -- https://en.wikipedia.org/wiki/Shock_(fluid_dynamics)

Reentry with blunt bodies works because most of the dissipation is occurring at the shock, at some distance away from the vehicle, allowing most of the heat (that must be produced from the kinetic energy of the vehicle as it slows) to be carried away.