Technically, as much as people like to believe otherwise there are actually some people are a lot more knowledgeable or open minded than they're given credit for. For example --

Suggestion: "We need giant laser shooting robots that rampages across every city and you have to defend the city from it's attack."

How would that not be a waste of time versus:

Suggestion: "Unlock chocobos and airship for more methods of travel, especially when Ishgard is related to battle content, we need quicker transportation and sometimes are low on anima."

So people who say "things are a "waste of time" generally mean in regards to something the game could benefit more from.