What if Kai was the original TV airing?

[Hellspawn28]

No it isn't.

Compare DBZ was 10-15 years to now, DBZ is niche in the US if you ask me. Just because there's a market of something that does not mean it can't be niche. For example, Godzilla is view as niche but there's a market to it. If there wasn't then the series won't be getting a big budget movie this summer with a ton of hype and the past movies would never get a home video releases. Same goes with anime series like Gundam since there's a market for Gundam despite Gundam not being mainstream since SEED ended.

How many kids shows back then had much character development?

Batman: TAS, Superman: TAS and Beast Wars comes in mind.

[ABED]

Batman: TAS, Superman: TAS
Not that much if you think about it. Batman's more or less the same from episode to episode. The biggest change in the characters is probably Robin becoming Nightwing.

As for Superman the animated series, I don't remember a whole lot there either. Don't get me wrong, both are great series, but the characters don't progress much.

[Valerius Dover]

Batman: TAS, Superman: TAS
Not that much if you think about it. Batman's more or less the same from episode to episode. The biggest change in the characters is probably Robin becoming Nightwing.

As for Superman the animated series, I don't remember a whole lot there either. Don't get me wrong, both are great series, but the characters don't progress much.

Yeah, Batman mostly had things reset by the next episode, including villains. The only villain to truly reform was the Ventriloquist. Superman had more plot progression going on, but I still think the only major change happened at the end of the series with people losing his trust and everything.

[SSJ3_Zack]

DBZ was so ground breaking at that time. No other children's show back then had the intensity, the character development or fighting choreography that DBZ had.
I'll put it out there and say that Kai probably would of been EVEN MORE popular than DBZ was back then. It has a more mature and accurate script, and the Yamamoto music is epic. Not to mention it skips the more boring aspects of the show and gets straight to the point. The children would have ate that up. This is of course providing that it was a hyped/marketed like DBZ was back at the time.

To the few that say that Kai isn't popular are being a tad foolish.
My nephew and all his school watch it (I detailed that in the Kai section). Heck a few weeks ago I went to pick my brother up from school, and at the time I was wearing my DB Hoodie and a lot of the kids at his school instantly recognised it from Kai. Not to mention I've worn it a few times in public and I always get a lot of children recognising it. Hell I once had a conversation with the grocery woman at Tescos and she literally said "I was wondering where I saw that before, that's from that Kai show my son watches."

[omegalucas]

Yeah, it was actually thanks to AB Groupe (the assholians who named Mr. Satan as Hеrcule) that made the Dragon Ball series so popular before US even had any idea what it was about.

They did make a lot of unnecessary changes to the script but at least they still kept the original Kikuchi score and the power level was 8000 not 9000. One of the popular being "By the power of Kaio-sama!" (instead of "I am Son Goku!!").

Love 'em or hate 'em AB Groupe is the reason that Dragon Ball is so famous in Europe and France gets the Japan Expo which allows its residents to try out the games of Namco Bandai before they're released everywhere.

Pretty much this.
FUNis version would be relevant for the US (and maybe other English-speaking countries... England had a different dub though I think), but AB Groupe laid the ground (for better or for worse) for most of the European countries' dubs.
I'd say the videogames gave much more awareness worldwide to FUNi's dub than the actual dub itself...