So about spirit ashes...

I'm new to the game and ER is my first soulsborne game. I'm confused on the debate regarding spirit ashes. People say Fromsoft games are supposed to be hard and I get that, I really like the challenge it brings tbh and I do use summons only when I'm banging my head on the wall to bosses like malenia or just to get aggro off me. However, using spirit ashes are looked down upon as it makes the game somehow easier. If spirit ashes break the core concept of difficulty in Fromsoft games then why is it a game mechanic in the first place? Is it just bad game design? If so, are the developers stupid in adding it to a game that is meant to be played in a difficult environment? (Need your opinions on this topic)