Sure, you can buy it. But should you buy it? Especially when there are far better and much cheaper alternatives.

Thats up to each individual to decide. But say you shouldnt buy because there are others that would need it more seems to go against the basic principles of supply/demand

He is just saying if you have local fiber and its priced similarly or cheaper it is illogical to get starlink, and he is right in almost all instances. This isnt a formal discussion,you kinda need to cut people slack and give benefit of the doubt where there is ambiguity or ask for clarification before going attack dog.

assuming one is stationary

Why would you pay more for a slower connection though (both bandwidth and ping)? And probably also less reliable.