Powering on/off amps with preamp trigger

Hi, I want to use my preamp trigger to power on and off my amps. I have read that people prefer to power on the amps after the preamp and power off the amps before the preamp. If I use the preamp trigger, then power off and power on would be simultaneous with the preamp. Is there a danger in this? If so, what are they and why do people prefer to stagger the power cycling of the amps and preamp?

Oh yeah, before any one says it, I am an indeed too lazy to take the extra step of turning on and off my monoblocks. Yes, this is purely a matter of convenience for me.