Bitcoin has had over 51% majority belonging to the chinese miners for years, and people ignore it , but yet when it comes to PoS ,
they pretend like every attack is more dangerous , when from my experience PoW has proven more vulnerable especially if you are not rich.
That is the propaganda you have to deal with on bitcointalk.org. You don't typically get unbiased opinions here.
Conclusion:
Security of any coin is only strong if the majority % that either mine it or stake it are altruistic toward said coin.
IE. No real difference between PoW or PoS in that regard.
More or less. But discussing the crazier "what ifs" helps to design better protocols.