I hope this is on topic, and trust it will be closed if it isn't.
Consider the following fallacious arguments:
There is an upper limit to the number of people the earth can support; therefore the earth is currently overpopulated.
X is a good thing; therefore the world would be a better place with more X (regardless of the cost).
If you stand still forever, you'll never get anywhere; therefore you should never stand still.
Is there a standard name for the sort of fuzzy thinking that underlies all of these? If not, does somebody have a catchy name to suggest?