who is the smartest person AGAINST bitcoin?

I've read the whitepaper, watched countless videos, and have come to the conclusion that bitcoin is something special. But more importantly, it seems people who are much smarter than me believe in bitcoin.

It seems that those against bitcoin are just ill informed. I often see statements like

• it's a ponzi scheme
• something something tulip mania
• what if someone shuts off the internet
• I can't hold it so it's not real
  
• it uses too much energy and is bad for the environment
• can't work as an actual currency
• only bad people use it for illegal stuff

Are there any people out there who really know bitcoin on a technical level and can see some flaw that holds up in an argument? A flaw that would actually prevent bitcoin from becoming the digital bedrock of our entire financial world?