Why is Vince Russo Controversial?

Russo’s booking style emphasizes "crash TV": frequent swerves, shock value, and unpredictable angles. While this brought success during the ratings war between WWF and WCW, it also drew criticism for poor storytelling, lack of logic, and an overreliance on shocking moments over long-term planning. His need to constantly have things happening on every show meant that heel and face turns and title changes and more happened whether they made sense or not.

He also frequently criticized traditional wrestling styles and downplayed in-ring action in favor of storylines and entertainment. His run in WCW (1999–2000) is often blamed for accelerating the company’s decline as convinced that every wrestling fan felt the same way he did, he worked overtime on storylines which “broke the 4th wall” and shone a line on just how “fake” wrestling was, in order to then portray other scripted events as “real” and therefore more shocking. If you think that’s silly and doesn’t totally make sense, you’re not alone as fans tuned out of WCW in their millions (literally millions).

In more recent years he has a contentious relationship with fans, wrestlers, and executives, often portraying himself as misunderstood or scapegoated. None of it is his fault, y’see. He was only allowed to do whatever he wanted all of the time with no limits or control and so how can it possibly be his fault?

Positives

It’s not all bad. He helped make WWF's product edgier and more appealing to teen and adult audiences during the late '90s. Along with that, he’s credited for creating or shaping characters like The Rock, "Stone Cold" Steve Austin, and D-Generation X. He was certainly a voice in the room pushing for those talents to be allowed to go further and further with their, pardon the pun, Attitude.
Under his writing, WWF beat WCW in TV ratings after years of being second place.

In my opinion, his greatest strength was always introducing more complex, serialized storytelling to weekly wrestling TV. Each episode of Raw felt like a contained product with a focused story running throughout. He kept up that practice years later in TNA even naming each episode like it was a regular TV show.
He also tried to give underutilized talent storylines, rather than only focusing on main-eventers - another big bonus. Under Russo, even if it didn’t always make sense, everyone from the top of the card to the bottom had SOMETHING to do.
He was also never afraid to try something new, even if it failed - a quality admired by some in a stale creative environment. 

Negatives

The negatives always far outweighed the positives, however. Overbooked & Illogical Storylines where he often threw in twists, turns, and swerves with little long-term payoff or logic became far more common once he was in WCW with full control and no WWF booking team or Vince McMahon to hold him back.
By prioritising "shock" over coherence (e.g., multiple title changes in a short period, convoluted heel/face turns) he devalued Championships: Treated titles as props rather than achievements, damaging their prestige (e.g., putting the WCW title on himself in 2000). By having a championship change hands six times in only four weeks, fans stopped caring who won them - it didn’t matter, they’d lose it again in a few days. That time scale is only an example I plucked out of the air. In reality, he often had championships changing hands far more often. The WCW World title once changed hands five times in two days. 

His time in WCW is widely seen as creatively disastrous, helping drive away fans and talent during a critical time. Critics argue he misunderstood what actually draws in wrestling: building long-term emotional investment through solid character development and in-ring storytelling, rather than the constantly moving, never sitting still ADHD approach he takes to writing.
People like Jim Cornette, Bret Hart, and others have been vocal in their dislike for his creative decisions and personal demeanor - he was a loud, obnoxious “bro” from Long Island who only got more unbearable the more successful he got.

Really though, his biggest negative is that he has a very xenophobic world view, believing that only Americans were worth pushing on TV. He was accused of racism towards Japanese, Mexican and black talents for years. On top of that, his treatment of women across all writing endeavours is undeniably problematic, treating them as lying, scheming sluts and sex objects with no other value. There’s also been plenty of homophobic and even transphobic content in his writing over the decades too. All in all, it’s difficult to imagine Vince Russo as a “good guy”. He is at best far more old fashioned and conservative in his world view than his edgy writing would suggest, and at worst he’s basically an incel edge-lord 4chan poster stereotype come to life.