Hilda looking back wasn't the only female protagonist from games which writters passed on in being used in anime in any shape or form. There is also Kris, Rosa and never regretted Leaf.
However in Hilda specific case main reason why writers didn't used her probably comes from fact of wanting to do some sort of reset, new start for pokemon series. Mirroring OS(namely Kanto style)in some ways suc as female gym leader joining Ash again. Ash catching more pokemon than usual aong with his characterization being dumbed down abit. Acting more clueless and immature which clashed with his previous growth.
Etc.
Which was mainly consequence of BW games going nthrough big revamp. Cutting ties with padst generations and pokemon from previous sagas for firtst time in history. Getting rid of contests and promoting mantra of new start, "fresh beginning" they seemed to be intended in going for.
With writers wanting to mirror games message as much as possible reducing continuity and links to history, previous characters and experiences Ash went through and got molded as person to minimum. In having only one character posessing pokemon starters, getting rid of Brock after what 12 years?
Not having presence of any older pokemon in first half of UNova accompanied with writing style which lagely differed from what people used to see in Sinnoh. Although arguably i appreciated lively, more energetic chemistry in main group, higher sense of unpredictability writers went with by breaking several patterns(such as Ash catching dark type, Team Rocket being organized, agile villains, main girl getting fully evolved pokemon right of the bat etc).
However to be perfectly honest if production team really aimed to go back to roots they could simply in that case reuse original trio which would be most appropriate candidates for it and make more sense. Something most fans which missed OS writing style in reality asked for, to see good friends which know themselves for long gathering together and building on friendship experiencing close bond, joking, clash and friendship they shared.
I don't think iris' pokemon would have been any better. Dawn's team consisted of almost all unvolved pokemon other than Manoswine. Iris would have had the same type of team back in DP.
Comparing Iris to Dawn is like comparing apples with peers to be honest. They are girls with largely different personalities, different careers and motives they pursue. There is nothing to indicate how Iris would had same pokemon team if she was in Sinnoh.
All the girls generally have in evolved and cute pokemon for most of their run.
Not quite. Iris had 50/50 ratio with evilved and unevolved cute pokemon(i just dont see Excadrill and Dragonite as small, fluffy pokemon. With Misty aside from Goldeen, Corsola and Togepi i would have hard time calling Staryu, Psyduck, Poliwhirl, even Horsea that much cute at all.
Looking back its kinda true how out of all main girls Dawn had most unevolved and cute, plushy pokemon which went better in correlation with advertizing. Since small, unevolved pokemon for some reason are usually most popular among small kids being impelled to buy such products.
As for Iris I think the writers gave up on her after she got her Dragonite. Besides meeting Claire she largely got stuck in the background for most of BW until she left.
Not really. There was rather big role focused on Iris and Dragonite in growing more accustomized to each other during events of Junior Cup.
There were episodes focused on Iris gradually earning Dragonite thrust such as in battling legendary Kami trio, like when blocking Thundurus attack herself to prevent her pokemon from getting hit.
Afterwards there were several episodes focused on Iris past, return to dragon village meeting up with her childhood friend Shannon, reviving bad experiences at Opelucid city. Showing Iris was treated as outcast which couldn't fit in within norms imposed by society leading to rematch against Drayden.
Iris played role in stopping Colress and Ghetsis in fighting Team Plasma and their attempts to revive Reshiram and controll pokemon through their own machine. Fought Ash Charizard.
Entered Marine Cup, There were episodes dealing with her pokemon like Emolga switching sides joining Team Rocket briefly and notorious ones such as Axew being lost.
While being present generally in most episodes interacting with Ash, Cilan and others.
So im not sure how was Iris background fodder after getting Dragonite?