Air carrier pilot reported LAS ATC does not allow aircraft to depart from the runway required to comply with climb gradients to avoid terrain due to high outside air temperatures.

Narrative

This is a safety and efficiency concern that I have noticed with LAS ATC. The Tower management and TRACON management seem to only care about the airport configuration that is the easiest for them. This does; however; have aircraft taking off towards terrain at temperatures that are well over 100 degrees. They give no consideration to aircraft operational needs; such as ETOPS flight that are climb gradient restricted off of 26R at high temperatures. Instead; they refuse to accommodate aircraft that need an east bound runway for takeoff or threaten a multi-hour delay. I have seen this; even when the winds favor eastern flow. I have taken off and landed numerous times in LAS with tailwind components barely inside of limitation because of their reluctance to turn the airport around. Instead we are having to leave passengers behind on long flights or plan a fuel stop. The bottom line is that their unwillingness to accommodate aircraft operational needs is creating an unnecessary burden on all that are forced to endure the repercussions of their stubbornness.