Isn't diamond a thermal 'short'? Rather than using liquid, why not use vapour deposition diamond to draw the heat down to a cold finger or TEC (Perltier cooler)

Isn't diamond a thermal 'short'? Rather than using liquid, why not use vapour deposition diamond to draw the heat down to a cold finger or TEC (Perltier cooler)? I know if it was that easy we would already be doing it, but I'm hoping somebody knows why. Probably because interfacing the grown diamond to silicon creates interface stress that leads to cracking or...some other reason... :: mutters ::