This seems to be the case for any summoned companion (Warlock's summoned imp as well). So far I haven't seen it start out as anything but level 1. Agree that the spell should improve as you level up, otherwise that skill will become pretty worthless in a hurry. The stock familiars start out awful (maybe do 1 hp of damage if they're lucky enough to hit, get killed in one hit) and the better summons will be obsolete in a few levels.
