A SpaceX rocket exploded soon after launch, but why did Elon Musk and his employees celebrate?

Subject :Science and Technology

Section: Space technology

Context: After a flight test of its new reusable Starship rocket ended with the craft exploding into smoke and flames.

Details:

The test was the first for the spacecraft manufacturer’s Starship spacecraft (the carrier) and Super Heavy rocket (the booster), collectively referred to as Starship.
The Starship represent a fully reusable transportation system designed to carry both crew and cargo to Earth orbit, the Moon, Mars and beyond.
The flight test failed due to the malfunction where the upper-stage Starship failed to separate from the lower-stage Super Heavy rocket.
The celebration is due to the fact that one of the major objective of getting the vehicle off the ground was achieved with a successful lift-off.

About SpaceX Starship:

Starship is a fully reusable spacecraft designed and built by SpaceX with the primary goal of sending humans to the Moon, Mars, and beyond.

Key objectives

SpaceX aims to use Starship to establish a self-sustaining human settlement on Mars.
The ultimate goal is to enable humans to become a multi-planetary species.
It also aims to make Starship reusable, reducing the cost of spaceflight and bringing down the price to a few million dollars per flight.
In the long run, the company aims to achieve full and rapid reusability of the spacecraft.