I think it is because Intel must have increased clockspeeds relatively late in the cycle - I expect Skylake-X must have originally been targeted at lower stock clockspeeds where TIM would have not been an issue.What a pathetic release Intel. I hope it was only panic mode and things get better. (I would Not void my warranty on a 1k cpu for higher clocks and lower temps by delidding.)
There is NO reason for Intel to NOT solder the lid except for getting their extra 25 cent.
Even the lowly, so-called cash strapped AMD spent the extra money for a high quality conductor.
What is weird is there are still persons that thinks AMD's TR didn't get noticed by Intel.
Intel can't even have a higher than 20 thread cpu hedt before AMD drops the 32 thread release.