Why is scientific theory really such much better than just a "theory"?

Anyone can have a theory. Some people come up with new theories all the time. If theories are not tested to verify that they have predictive value, then what good are they? Another aspect of science is that, if you have two theories that both adequately explain some phenomenon, then the simplest theory wins and is accepted as the "correct" theory. For example, it may be intellectually entertaining to think that the universe revolves around the earth and anyone can make plenty of observations that support this theory but, for at least the last 300 years, there has been scientific concensus that this theory is wrong.