As a healer, is it my job to DPS? A new perspective.

[Lambdafish]

Exclusion is classed as abuse in RL situations

There is a difference between exclusion and grouping. Different parties want different groups of people with different abilities. Are you seriously suggesting that if you aren't qualified for something then you are being abused?

If you really are interested in psychology, look up A theory of sequential reciprocity (Dufwenberg and Kirchsteiger) and Borstein's Ultimatum game, it is an interesting look at group behaviour within games.