We can choose only 3 attributes to upgrade every level up. If you want to increase the figure on initiative, you need to sacrifice some figure of other attributes like HP, damages or stamina. And it would need a large figure of initiative to reach at the first one of every turn. Or you need hire a high initiative merc at the first place.
Initiative is not completely useless, but it won’t compare to other attributes. So, this means most of the players won’t care about that attribute.