You only need to follow this advice if you (the player) have an antagonistic relationship with your DM.

Your character might suffer from the ideas you give them, but the player should get enjoyment from the situations you got.

More often than not the best answer to "Wouldn't it be hilarious if X happened?" is "Would it? Let's see! ..."

If you want to play a fun dynamic world, DO give the GM ideas, you never know when you'll turn a slightly cool idea into a story arc, because the GM feeds off your excitement.

"Come on everyone, we have to solve this riddle! What if the missing Scepter of Glorificon is in there?"

"No we have to turn back! The lich ghost of the octo-king could be waiting for us, seeking revenge after we defeated him in his aquatic lair beyond time!"

"GM, I ask the old sage NPC if they know what's past the riddle."

Me, furiously scribbling notes and scratching things out: "Oh uh, they laugh heartily at your comments about the lich ghost. 'Hohoho, the octo-king back so soon, that's just ridiculous! But I know not what is beyond the door, the ancient prophicies say it is both what you most fear and desire...'"

On a serious note this is just bad advice. Giving the DM ideas to make the game more fun is a win for everyone.

I have way too much fun reminding the dm of things that screw us, the party, over. It makes it kinda fun!

(absolutely DO feed the DM plot ideas, actually. They love it. :3)

A recurring villain was introduced on the first session. She was a human pirate captain with very pale skin. One of my players immediately thought that she was a vampire.

...

So she is a dhamphir now. (Couldn't make her a full vampire, they met her in daylight.) Not like it gave her much of a boost except for a climbing speed and spider climb anyway.

Joke's on you, I'm doing that shit on purpose

If I had a nickle for each time i've thrown out pages of notes because a player surmised something really cool out loud, I'd have many nickles.

sounds advice... since when?

galaxy brain: DM your own campaign while simultaneously playing it as a PC, just letting some schmuck think he's in charge.