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

[Sleigh]

tl;dr of why SMN is the worst DPS:

- Almost completely outclassed by BLM (burst, sustained DPS, no resource issues - would require VERY heavy movement or multi-DoTs for SMN to beat BLM) which is huge when considering a job's position if you have an alternative that does almost everything the same or better in effective terms
- MP issues lowering their already low-end DPS (unless you can multi-DoT a lot but BLM wins anyway)
- Multi-DoT situations often too short for the ramp-up (ironically SMN was better in this area when we weren't overgeared but then it was more a liability to T12/T13 phase pushes anyway)
- "Utility" is either covered by the existence of SCH having Super-Virus, meaning it doesn't matter what type of Virus SMN has since every group has the one Super-Virus user they need, or you don't need it currently (pets can't do stack mechanics, Resurrection in FCoB is more or less only used as a means to prolong a wipe anyway for learning purposes during progression). The most you can say about SMN utility is it has a slightly faster E4E which should never be make or break (and TBH 99% of groups don't have such E4E upkeep that it's used on CD by all, even in high end groups)