It was before my time, but my understanding is that there was this one anon from a few years ago spamming JASMINE IS PURE threads everyday so some other anons starting spamming Houndoom to shut them up, but soon the Houndoomers became even worse than PURE anon. Then hammer thing came, then fairly recently the ledian thing started.
I think part of the excess torture is due to some genwunners being salty that someone from "West Kanto" got so many appearances outside of her gym and tournaments.
Gen II>Had a subplot involving the Lighthouse and Amphy
Gen III:>Appeared in the audience of in Pokemon Contests
Gen 4:>DPP>Gives the Player Waterfall at Sunnyshore>Appears in Super Contests >HGSS:>Appears at the Fountain with Erika >Appears at the Olivine Cafe >Appears as a Pokeathlon opponent >Trades the Player a Steelix (different from her battling one) and accepts any Pokemon in return
Also, She was one of the only girls Brock feel in love with twice. (once in Johto and once in Sinnoh), when even Whitney (the Incredibly Pretty Girl) didn't have that affect on him.