Honestly for me it's not about the health costs. I don't mind them, and the dev team found something thematic for the character/class. Does it feel the best when playing? Not always but even if it's not optimal I still kinda enjoy it
I see where you're coming from with the intent versus the execution and I don't have problems with the health cost in combat. However, this was a form of skillet expression that wasn't tied directly to a DPS increase like most of the games, Skillet expressions (i.e. animation canceling guardian great sword five for more DPS) . I just don't like the feeling of not being able to use mobility skills outside of combat because it will put me in combat and actually slow me down. I really enjoy necro as a class, but it was not. One of my most played because of the fact that it lack mobility skills and it is one of my favorite parts of the abilities in this game.
Additionally, having something in the patch notes to tell us that this was happening would have been nice if this was a change they had planned on making.