alt Hacker NewsMourn not. These were purpose-built structures erected in record time to support a single program (and pressed into service for Shuttle & friends). They were first so they were by definition pioneering, but we've learned a lot since then.
The sad part isn't that they're gone. The sad part is that we didn't make them obsolete until just recently.
To be clear, NASA has an entire field center dedicated to rocket testing (https://en.wikipedia.org/wiki/Stennis_Space_Center). This is where everything gets tested now. You may remember the "green run" tests of the SLS - those happened at Stennis.
Stennis didn't exist at the start of the space race or Apollo. Marshall is colocated on Redstone Arsenal, a legacy of parts of NASA being bootstrapped out of the Army ballistic missile program. Marshall had test stands because that era of NASA (aka von Braun) sought to colocated engineering, prototyping and test.
One challenge with continuing tests at Marshall is that... it's actually really close to population centers. Large engine tests would be ridiculously disruptive. There are comments in the Ars article noting that people living in Huntsville could hear the demolition work.