Why Order of the Profane Soul Blood Hunters cast warlock spells but still use Wisdom as the spellcasting ability?

sorry if you’ve answered this before but I’m curious why you chose to have Order of the Profane Soul Blood Hunters cast warlock spells but still use Wisdom as the spellcasting ability? Because an additional Stat to focus in makes the order very difficult to enjoy. Wisdom is a secondary ability score for the BH, so it’s a mechanical choice

— Matthew Mercer (@matthewmercer) January 26, 2018