The women of Troy document was very good. Not sure if it is still up on SHO or wherever it was (hard to keep up with all these streamings), but you should watch it if you can.
There are other women that have dunked in WNBA games but all of the dunks have been, "Rimgrazer off 1" or "Basic Two Handers off 2 (Rarity)."
Dunks don't happen often enough, with enough elevation, for them to be considered anything more than "Power Layups."
Why would someone call the WNBA Boring?: Because the NBA is the standard. It's that simple. It's hard for many to not look at any form of Pro Basketball and not want to compare it to the NBA. It isn't even just the WNBA. It is Euro Basket, it's the Big 3, G-League, TBT, Local Pro Ams. If you have the word "PROFESSIONAL" in your description, it is hard for anyone to not think of how it ISN'T the NBA.
The same with any other product that is so dominant in a certain field.
But specifically with the WNBA, the lack of athleticism displayed (compared to the NBA) is essentially what makes people not want to spend their time watching it.