Can someone give me an in-depth explanation why Summoner is arguably the worst DPS?

[Avia_Frost]

Why not play the job/class yourself and come to your own conclusions?

This ^

A lot of the posts on this thread were made by people who don't even really play SMN as main class and think they know it all and sometimes described the class incorrectly/not being played at its best.

Good smn will do just as good dps as good blm, but it's just rare to find one, especially with so many changed to play other classes.