We have all heard of Dragonball (of Z I mean, noone watched the original), it was a huge name in the 90s, that introduced anime to the rest of the world through the only good dub I've seen today and is responsible for inspiring hundreds of other anime and mangas. So why would anyone hate it?
Well, as was mentioned, Dragonball WAS responsible for many of today's mangas, creating (or at least making famous) various stereotypes that lasted though decades. Some examples of the wonderful stereotypes that Dragonball made norm include: 1)Stupid protagonist in shounen. 2)Evil is stupid. 3)Death has no meaning. 4)Females are all annoying tsunderes. 5)Overly annoying episode-long training sessions. 6)Abilities explained mid-fight to the opponent (...)7)Transformations (ok that can be done right, but the way dragonball did it, definitely wasn't, with the exception of Buu).7)Overly-Recycled animations.8)Overly predictable plots with the villains smiling evilly and laughing maniacally even when in disguise, reinforcing point 2, but also for some reason actually fooling the "heroes".9)Complete and absolute lack of character development.
I could go on.
As you see, what I truly dislike about Dragonball is the legacy it left behind. Dragonball was an example to be followed by everyone else to be sure, a very, very bad example. Lazy writing, a despicable presentation of females (that finally started to change in shounens thanks to Fairy Tail), brain-dead characters, half-assed animation (I'm looking at you One Piece). Dragonball was in all aspects, definitely something intended for children. "But Dragonball has so much violence!" You don't say. But guess what, freaking Tom and Jerry also has a lot of violence (and with about the same amount of actual deaths as well), yet noone questions Tom and Jerry being a kid's show just because it has violence in it. Violence doesn't make things mature when it has no consequence people. Violence has meaning when it can create PERMANENT damage, physical or emotional. An anime where 2 people make punchbags of each other and 5 minutes later walk it off isn't an anime that should be proud of its violence. If anything it's insulting it.
The funny thing is, now that Dragonball Super is being released, everyone is whining about how bad it is. What really gets me going, is how DB fans complain that it's totally different from what they grew up with. Really? Is that how you feel about it? Because personally, all I see is EXACTLY the same product you grew up with. Now however, you have been exposed to actual "quality", even by accident, and can see DB for what it truly is: Trash.
Dragonball's glory is long gone. With the internet connecting our stupid brains together and forcing us to hear the opinions of others as well, a piece of crap like Dragonball will never reach fame again. Almost all of its descendants have long since surpassed it, learning from the mistakes of their father and not repeating them. Those include Fairy Tail, Bleach and (it saddens me to say it), even Naruto. Today's writers will struggle to produce intelligent plots, intriguing enemies with personalities that go way beyond "bad for the yolo", and actual relationships between the characters, making them sympathetic and memorable. In other words they will do all the things that Dragonball never did, and never will do.
"But then why do I have such fond memories of the original?" For the same reason you have fond memories of Pokemon, Sailor Moon and even Ice T. Because of nostalgia. The number 1 enemy of intelligence and objectivity. Through the spectrum of nostalgia everything seems nice and ideal, since it was a simpler time back then. That's a lie of course. The 90s were just as complex as the 21st century and probably a bit dirtier. YOU however, were younger back then, and as a result STUPIDER, which made you unable to perceive the world correctly. And of course with the years passing and all the bad memories fading away into oblivion, Dragonball, in all its majestic CRAP, becomes in your brain a wonderful sweet memory.