Seven hells what is wrong with you people?

The one consistent thing is that Summoners summon, usually great honking magical creatures.
Sure the mechanics vary and the caster isn't always called a summoner, but the practice is the same. Through item or contract you expend your energy bringing them into the world, and they blow shit up for you. You summon, and sometimes support (thou in an mmo you would have to), and they do all the damage.

This is one of the few in the series where the summoner doesn't really summon anything, where the caster does all the work.
It's like having a Dragoon but finding out that they don't use spears or jumps, or a White Mage that doesn't use white magic and barely heals. You wouldn't bloody well call them a Dragoon or White Mage now would you? Even if they work well in whatever skill set they have, they still wouldn't fit the role, they would be that job in name only.