That is a big heap Chernobyl level toxicity. Playing as you describe is not how content, any content was designed. It was designed with the expectation that players would use most of the skills/spells available to them. Developers generally are not building things or giving players abilities you aren't meant to use.
Just because you can clear something in the allotted time does not mean it was intended to be, and just because something can be cleared by running around casting scathe, in an albeit slower pace, does not mean it was originally designed to be done that way.

Choosing to play that way with others is at best disrespectful to others' time. This is toxicity in one of its higher forms because it tries to flip the script on the typically toxic elite savage raiders demanding high dps, when in reality its just a bunch of normal people trying to play and get activities done in a reasonable amount of time.