The issue with pet damage is that everyone in this game is convinced that they are more skilled just because they press more buttons... SE caves to that mentality, so they can't just boost Egi auto attack damage, for example, as that would just have everyone complaining about SMN DPS being too high because their pets do too much "AFK damage." As a result, they've resorted to tying more and more things to more and more manual button presses... You're reaping the results.
EGI Assault I/II
Ahk Morn
Bahamut not attacking unless you spam Ruin III's
etc.
On the flip side, they cannot really increase nuke damage directly, because the actual balancing and differentiation across the caster DPS are relatively weak (as they all start to feel like Wizards, frankly).
A DoTs focused-class isn't't a good idea in this game since most non-raid content is run by mass pulling everything. A DoT-focused class is going to be worthless for most casual players... Especially without an actual Tank Egi to keep MOBs off of it, since it won't be bursting things down. Even many of the MSQ stuff are basically solo DPS checked. Don't kill the stuff in time, 9999999 damage, thank you and try again.
If we're going to be frank, this class was badly designed from Day One, and only put in to fill the EQ/WoW Mage/Necro/Warlock niche for players who like playing caster pet classes (as those have been staple in MMORPGs since the beginning). It is a quota job, and they don't have a clue on what they're doing with it - which is why every expansion comes with another "rework" needing a major patch to "fix" it.
And a 120sec Recast for a 15sec 5% damage buff is awful.