Ah, the old -science will all be wrong in 20 years...
Which is wrong of course, we still make use of Newtonian physics hundreds of years later, and were you to count mathematics, some aspects of mathematics date back thousands of years. It's fair to say that 20 years from now we will still accept phylogenetic trees and we will use physics that allows us to build computers. Science is a process of refinement, a spectrum of probabilities
The strength of science is that it can in fact discard ideas quickly. If a model is no longer useful, out it goes, or it is altered. I find it odd that the parent assumes that because science has procedures built in to allow it to change when it is wrong, that this somehow equates to astrology therefore being right. Eg science will be wrong in 20 years which it wont)==astrology is right. This does not follow.
Science has predictive power. Anyone can replicate its results if they replicate the conditions of the experiment. With astrology on the other hand, lots of us have tried it, and it doesn't work. It doesn't stand up to testing. If it worked for everyone, it wouldn't be an issue, but it doesn't. Sure, there's a percentage of people out there who claim it work, but that's to be expected in a large enough population as a statistical probability. You'll find people claiming garlic cloves ward off the flu too. What it comes down to in the end isn't just that such beliefs are wrong--they simply aren't useful for the most of us.
Of course when the phrase 'be open minded' comes out, this translates as 'crowds who believe in anything for thousands of years can't possibly be wrong, blindly follow them''. When the bandwagon fallacy comes out, you know the ego is at work. Let's talk Tim Leary. Science is the real, ultimate ego death. There's no room for ego in determining objective reality, because objective reality doesn't work the way one wants it to.