Why no heated gear?

Sitting here listening to The White Stripes with the tubes glowing, gear nice and warm, and sounding fantastic. All but two hours ago the system was cold and sounding rather unimpressive, as it does when cold. I got to thinking why don't manufacturers add heating elements to equipment to bring it too optimal temperature quicker. I remember reading about an esoteric speaker manufacturer that did this to his active speakers to eliminate that "cold" sound. That's all I have ever heard about it. Now I know I could turn the system on sooner when I want to listen but we all have those last minute listening sessions. In reality I should switch to SS and leave it on all the time, but my Mc275 is too good to get rid off. Please post your opinions.