Columbus deserved to be laughed at. People of the time period knew how big the Earth was, and they knew that he would never make it to India like he wanted to do, and they were right. Columbus got lucky that there was a giant unknown land mass there (which he incorrectly thought was India) because if there hadn't been he would have starved to death.

Survivorship bias. If I had a nickel everytime I saw that argument from some conspiracy nut...

I very much agree. It's nearly impossible to know in the moment which it is.