Very good video. I approve.
I don't see why you think it's about religious people at the beginning. Although yes religious people usually fall into the "believe in something supernatural" group, but there are plenty of non-religious people in that category as well.
There seems to be a wide spread misunderstanding of what open-mindedness means. Many people seem to think it means accepting anything that comes along. It doesn't. It simply means being willing to consider anything, not that you'll accept it. Anyone that says it is possible to be too open-minded either doesn't know what being open-minded actually means, or they are using the phase where it's not really about an excess of open-mindedness, but about a lack in skepticism. There is no such thing as being too open-minded. No topic should be off limits to honest rational consideration. However, it's important to also be skeptical
Speaking of skepticism, there also seems to be a wide-spread misunderstanding of that term as well. It doesn't mean rejecting anything that comes along. It means requiring evidence or reason before just accepting things. Skepticism is a good thing when coupled with open-mindedness.
You could think of like this:
skeptical
A-----------B
| | |
open-minded |-----*-----| close-minded
| | |
C-----------D
gullible
If the goal is to have as many true beliefs as possible and as few false beliefs as possible, then "A" is what we should shoot for. "B" rejects everything and therefore would hold as few false beliefs as possible, but would also reject true beliefs as well. "C" accepts everything and therefore would hold as many true beliefs as possible, but would also readily accept false beliefs. Both "A" and "D" accept some things and reject others. The difference is the criteria by which this decision is made. "A" rejects things that lack evidence or that are illogical. "D" rejects things because they are unwilling to consider that they might be wrong, and thus will only accept things that agree with what they already believe.
Also it's worth mentioning that everyone starts out at "C". (this is the state that children generally hold, and they typically move away from it as they grow older.)
@Kobuk: Unless these "crackpots and nutcases" have good evidence to consider, then you are completely justified in not believing them. That doesn't make you close-minded.