4th job Single Target DPS

DPS doesn't mean we take an average over a second of attacking. You take a long experiment time, sum up all the damage done and divide by the time in seconds. It makes no difference.

Take for example F/P mages, to get to their maximum theoretical DPS they have to cast poison mist every 40 seconds, fire demon every 15 seconds and paralyze in between. Just by using those 3 skills you'd take more than a second. The DPS on the table takes into account the time required to cast those skills to keep DoT working and averages out all the damage done.

For all it's worth we could be doing DPnS (damage per nanosecond) or DPY (damage per year) and the numbers would mean exactly the same thing. It's just a matter of which number is easier on the eyes (no one wants to read numbers like 0,00000000000000121242136 or 238749238759827398572983759287395827 for the two cases I mentioned, respectively).

I know, I'm just saying why people say that in the first place.