That's a snappy one-liner but it doesn't address the real concerns.
First of all, subsonic lift is well understood and has been for decades. The answer is much more mundane: The Artemis mission profile does not require payload doors that open, no Canadarm, no requirement to service, launch, and/or capture satellites in orbit, and so like good engineers they designed the minimum vehicle that satisfies the requirements.
Also, the Shuttle was actually much more expensive to reuse than originally predicted.
