Isn't it interesting? Why would moon do so or why was moon made to do so?

Yes, the Moon provides some protection to Earth from asteroids and other space debris, but this protection is limited. The Moon can act as a shield in two ways:

Direct Impact Absorption: Occasionally, asteroids that might have otherwise hit Earth may strike the Moon instead. The Moon’s surface shows signs of many impacts from space debris, which could have potentially hit Earth if the Moon were not present.

Gravitational Influence: The Moon’s gravity slightly alters the paths of asteroids or comets that come near the Earth-Moon system. However, this effect is relatively small compared to other factors that influence an asteroid’s trajectory, such as the Sun's gravity.

While the Moon does provide some shielding, it's not a defense system, and many objects still collide with Earth despite its presence. Other factors, such as Earth's atmosphere, play a larger role in protecting us from smaller space debris.

Why does it have visible impact marks? The earth has them as well, but the earth is a "live" system: seismic activity, wind, rain, forests, erosion, etc. that blend them in (though some are visible). The moon is a static system. The footprints the US astronauts left on the lunar surface, 55 years ago, remain undisturbed.