Besides her being squishy (like most mid ap champs) why isnt she seen in pro games?

Cool story bro, tell it again.

Pretty sure most people don't play her in top tier play. She lacks range and CC, which are critical components of an AP Carry fitting into most team comps.

Scarra, Tiensi, and Judy Monica are among the few top rated players who count Kat among their mains, and Scarra is the only one I've ever seen compete professionally.

pretty sure I saw her banned in a championship game.
pro gamers are better at counter pickin her and stunning her ult.

also pro teams have carefully crafted team comps, where every champ fills a specific roll. They arent crafted by just throwing together the strongest champs. Maybe the rolls the pro teams were looking for, there were other champs that filled them better than Kat.

Doesn't have CC, unlike Orianna, Cassiopeia, Karthus, etc. (also, being melee sucks)

That said, a few pro players (scarra, reginald) were picking her up.

She... is picked.
She's actually on the strong, on the verge of op side.
She's just on the not-fotm-yet stage.

Because new Kat can NOT deal with anybody who plays the "passive farm, agressive harass" game. She does well in soloq because the meta is "agressive farm, not too agressive harass".

I think any player who understands this and doesn't pick karthus can annihalate a Kat in lane at least 90% of the times reguardless of player skill.