The fuse was added specifically because before that it was even worse than it is now, instant throw + no fuse = no way to dodge. You CAN dodge them, but you're still going to take a bit of damage, and the ability of the incendiary to deny cover is its strongest attribute. Volks can close in, throw a grenade and force the other squad to move exposing them to negative cover and damage to win the engagement.
The incomplete dodging thing is same for every grenade. Even the top players can not doge HE grenade perfectly every time, they usually took reduced damage like 20% ~ 30%.