Like @gibson5413 said, if people dig running OD's into high gain amps more power to them but for instance, my JVM410 OD1 Orange, gain at noon, the way I set the tone controls, res and pres, the way I play...I don't have a need for an OD.
Same with any other high gain amp I've owned that has lasted with me for a long time, I just prefer to get what I can out of the amp. Don't get me wrong I grew up (early 80's) running an OD or stacking OD's in front of Marshall 4 input MKII's and JMP's so I'm not anti OD but when rack preamps and then amps started having enough gain without having to use an OD, I loved it and have since.
For shits and giggles I've even busted out some of my old OD's to try and work in with the JVM and messing about it's never lasted more than a few minutes as I love the tone and feel without them.