It baffles me that people actually think that "culture" and "religion" are two separate entities, as if one had
nothing to do with the other. Contrary to this naive belief, religion is part of culture and culture is always affected by religious beliefs. They are constantly changing, mutually and interdependently, and the idea that there is a "pure" and "original" version of a religion is plain stupid. Islam is very much affected (duuuuuhhh!) by the arab culture Muhammad live in, which is evident by the fact that a lot of rulings in the religious rexts are only relevant to specific arab customs of that time (for example al dhihaar or relatives by "suckling"). So from the very start, Islam was never "free" from culture

I use this argument with cherry picking progressives, that Sahih Islam is the Arabi version from centuries ago, and the Taliban have it right, while cherry picking, themselves. Usually they are the most guilty of innovation, though they seem to have blinders on when you bring it up.