Why change the ability to block biter/spiter spawners with pipes/walls?

[JackTheSpades]

So, in the 2.1.7 changelog they revealed that you can now no longer use the trick to place pipes/walls around a spawner to (permanently) block spawns.
This isn't really a for or against debate since it is a niche use case anyhow but I just wonder why they decided to change it?

In this bug report Rseding91 specifically said it was intended and then after half a year staff came back and decided to patch it after all.

Have they ever said why?

[Rseding91]

I mostly deal with reports and address them according to my understanding of how the engine mechanics are supposed to be working. At the time I didn’t know about or care about achievements and nest blocking. The engine was programmed so that if a nest didn’t find a spawn location it just wouldn’t spawn biters. So it was working correctly as far as anything code wise says it should.

Later, others that did know about and care about achievements saw it, and decided that it shouldn’t be possible to do as it trivializes the entire point of the achievement.

[sarge945]

I generally agree that clear exploits should be fixed for gameplay reasons