Yes, it is. So is pole climbing and crossing the street.
Regardless, there is NO excuse for using a generator improperly.
As someone else said: With the genset running outdoors, run a heavy extension cord into the dwelling and branch-off other cords to vital equipment.
Unless a PROPERLY installed transfer switch is used, leave the house wiring ALONE!
Common line safety practices include insulating gauntlets, commoning all conductors and bonding them to ground.
Anyone that backfeeds to the grid during an outage DESERVES to have their genset FRIED!
JR
26-yr lineman