I'm not having much luck with this question in music production circles, it very quickly goes into personal experience and received wisdom.
Alas, those audio/music forums are populated mostly by dilettante amateurs where the "received wisdom" bounces around the echo chamber until most people just accept it.
It's commonly said that a dynamic microphone is better at rejecting background noise / room sound / reflections compared to a condenser microphone. I don't understand why this should be the case.
From an strictly scientific perspective, the major difference is sensitivity. Which is mostly the result of the passive nature of dynamic microphone where the sound wave itself must move the diaphragm (and attached voice-coil) through the magnetic field. vs. a condenser microphone which typically has a much more compliant diaphragm where the motion of the diaphragm is sensed by non-contact capacitance.
The result of the lower sensitivity is that the dynamic microphone will be unable to pick up quieter sounds like ambient noise and acoustical anomalies. AND it will force the user to speak louder for an equivalent signal level. And that will further enhance the perception of the dynamic microphone being better at "rejecting background noise, etc."
When I look at the polar response graphs for different mics, I don't see any pattern that would let me determine that I'm looking at a condenser mic or a dynamic. They're just all over the place (you can get a shotgun condenser and an omni dynamic for example). So if the polar response isn't characteristic, what else could make a difference? Maybe it's just that there are lots of dynamic mics that have a tight polar response and lots of condenser mics that have a wider response, so when you look at a typical mic cabinet in a studio, that rule of thumb holds. But people (and manufacturers) talk about it as if it was an intrinsic thing. I'm interested to find out if I missed anything or got anything wrong.
As you perceive, the polar response is determined by the physical design of the microphone case, completely independent of the capsule type (dynamic vs. condenser, etc.) Certainly, there are different designs, polar patterns, sensitivity, capsule type for various applications.
For example, we often use "shotgun" microphones for relatively distant pickup during cine/video production. Because of the expected low audio levels involved, these microphones virtually always are designed using condenser capsules. At the other end of the spectrum, certain microphones are designed for "close talking" in high-noise (and often rugged) environments. So the more rugged (and impervious to humidity) dynamic microphone capsules are typically used.
Because condenser capsules are extremely high impedance and produce a very low signal level, they require active amplification and impedance conversion. So they require power for the active circuit. A convention using 48VDC was devised by Neumann GmbH and Norwegian Broadcasting Corporation, NRK in 1966. It was subsequently established as DIN 45596 standard.