Before I go into why I hate this bag, I admit that there are style aesthetics where this backpack works: perky, creepy-cute, kawaii, cartoony looks. "Cute" dark looks put unexpected symbols in unexpected places--silly cartoon prints, ungoth things like unicorns and whatever, plus macabre things like coffins and razors and that sort of thing. I think it's an aesthetic that's supposed to be laughing at the dark side of life. As someone who does not feel joy and never laughs, this aesthetic irritates me, but from this spawneth the coffin bag.
Outfit coherency problems
It either came from this aesthetic or it came from people looking at a regular backpack and panicking. "Not goth enough..,people will think I'm a poser. Goth is a lifestyle...I can't have an ungoth backpack!"
You can. It's ok. And that's the main reason why I hate this bag. Not every item you own has to "be scene." And if you don't dress in that cute aesthetic, having an LOL COFFIN on your back is instantly going to make you look like you don't know what you are doing. Coffins are spooky, yes, but in that Halloween way. Coffins don't look that way except in cartoons. If you are wearing a serious look, do you really want this complicated postmodern "macabre/cute" accessory mucking up your outfit?
Was the choice intentional or did you just need to wear a bag, any bag? If you just need a bag, may I suggest my Purses I Love post.
There's also like this weird peer pressure to own this bag that makes me hate it even more. Like, everyone owns this bag, even if it doesn't fit their aesthetic. When I screen-capped the above photo on Hot Topic, there was a pop-up saying 10 people bought it in the past day.
Structural problems
But what if you need a backpack? It's also a shitty backpack. Backpacks are a utilitarian tool that are used by parents, students, travelers, people carrying bulky items like books and board games to gaming night, hikers, and the like. The shape of the coffin bag isn't useful for anything rectangular, which many things are. If a book or board game fits in this bag, it will no doubt deform this bag. It's also narrow at the bottom and wide at the top, so you basically can't utilize the full size of the bag unless you have things that will fit this exact shape--a water bottle and a sweater wrapped around the bottle? Good luck getting your keys from the bottom of the bag.
The other thing is that no self-respecting quality brand will make this stupid bag, so you will have to get it from a "goth brand," which will always ALWAYS be made of shitty material and shoddily made. They will be made of plastic, which will not look better with age and use the way canvas or leather will. They will cut corners on structural support and hardware, so you'll probably get a bag that's basically cardboard with glued fabric on it. This will make you look like a teenager. I personally would never spend serious cash on a quality leather purse--I'm fine with my either free or $10 canvas bags. You know what? My bags never look cheap and are good for adulting all the time.
(I need to do a dedicated post on how shitty goth brand purses are...I've never owned one, but the YouTube reviews confirm what I suspect just from the product photos)
In conclusion...
Not every item you own has to be goth. A functional item like a backpack doesn't need to be goth. If you want to look put-together, don't wear a style staple from an aesthetic that you aren't dressing in. Perky goth items are so overbearing that even one of them will infuse your outfit with humor and joy. If that's what you want...do you, lol. I'll be staring at this dark void instead: Sadness. Despair. Sensible canvas bags that fit all your things and go with every outfit. Nihilism.