The over used and beaten to death topic: fan service. Completely valid reason to quit as someone who is fine with fan service.
This is going to be long because I’ve been racking my brain over why I don’t want to finish the show over others that have way worse fan service and because I’m having fun with the thought exercise.
TL;DR at the end.
I got through both seasons because Atsushi Ohkubo made it and there are plenty of enjoyable moments, fun characters, and fun fights. I’m super happy he got to put out another story and it’s had so much success.
I won’t rewatch those seasons or finish the show because of the fan service, but that’s a really poor explanation of what I think the issue is: comedy and seriousness is an incredibly hard balance to strike.
I’ll add in High School of the Dead and Soul Eater to explain.
It’s a fan service topic so we’ve gotta bring up one of THE fan service shows, right?
From the most unnecessary panty shots to the dumbest way to stabilize a rifle, HOTD is out there but it’s crazy. It’s full of action, it has some comedy, but not at the most crucial times unless it’s dry humor.
The closest character I can compare to Tamaki (love or hate her we all know Tamaki is the sticking point with this show) is the nurse. She’s ditzy, like Tamaki she does help but not in a fight. The difference is the nurse brings two things to the table the main cast cannot safely get on their own: someone who can drive at any time because she’s not spending her energy fighting, and someone with a one time used connection to get ridiculous weapon upgrades.
Tamaki brings one thing that you almost can’t replicate with any other character: her damn near immunity to fire.
They both have their value to the group, the difference from a viewer perspective is the execution: one of the only times we see the nurse be funny in a high stakes situation is when she describes an antagonist as a creep or something. It’s just a one off line that’s accurate, unexpected, and doesn’t distract from the problem facing the main cast.
Tamaki on the other hand will interrupt fights and make things worse for her friends except in two situations when she basically chases a would be big villain away with her nudity. All of these happen in high tension moments that just make the seriousness evaporate.
Closer to home, there’s Soul Eater. I can think of four characters that can be likened to Tamaki in terms of comedy:
Kidd, the Thompson sisters, and Blair.
Kidd wastes his time doing his little poses with the sisters and has a melt down when things go wrong at the beginning of the fight, not in the climax unless his melt down comes in the form of some blind rage that results in him going over the top to finish the fight.
In addition when the Thompson sisters are being funny (Liz crying when her sister puts her in a mummy’s mouth) they’re still fighting as an effective team.
Blair is way closer to Tamaki because in the very beginning of the show she’s introduced as a powerful witch. A huge fight to kick things off. Then nothing. It’s the first scene though, we don’t know anyone. We don’t have any actual tension built up. We just got the back story for why the main characters are there.
When we finally do get a cross between comedy and seriousness it’s a “fight” between Blair and five witches fused together who should have no problem at all killing the normal people in the area. Their antics are out of place for the scene but Blair isn’t holding her friends back and she is effectively holding off five lower power witches.
The only time I can remember Tamaki doing that is when she was being tortured which does admittedly show off her fire resistance but it was not a comedy scene in that moment.
The difference between Fire Force and these shows can once again be poorly summed up with two words: comedic timing.
Edit: That is a huge deal for people. If anyone has seen Inglorious Basterds, the back story behind that movie perfectly illustrates this topic. It almost didn’t get made because Tarantino couldn’t find a native German speaker who was fluent in English and could get the comedic timing of speech down in English. Christoph Walz saved that movie as a native English speaker who was fluent in German, bypassing the comedy issue.
TL;DR: The show does a lot of things great but that’s a hard balance to strike the more you mix seriousness and comedy together. Fire Force just hasn’t done it as well as it could.