> What reason is that?

Groovy made Java slightly less painful too use, but added its own warts.

Today we have languages which are better than Java without adding all of Groovy's mistakes.

> They're an Apache supported project now.

You mean the place where software projects go to die?

The Codehaus implementation of Groovy was only voted into Apache a week ago, and still needs to complete the infrastructure conversions which could take months, or longer if problems surface. Its project manager Guillaume Laforge has been making fraudulent claims about the consensus of the "Groovy Community" on joining [1]. He's redefining "Groovy" to be whatever's in their particular codebase, instead of a reference implementation of a spec as its creator James Strachan asserted right up to his last ever posting on the Groovy mailing list [2]. From there, Laforge is redefining the "Groovy Community" to be whoever's committed to that codebase, instead of whoever's contributed in any way to Groovy, including people who've haphazardly worked on other implementations of Groovy and those who've mainly written documentation. To further support his new narrative, he recently withdrew from the expert group and lead role on the JSR-241 [3] that defines a spec for the JVM version of the Groovy Language. I suspect the Apache mentors of Groovy such as Roman Shaposhnik, Bertrand Delacretaz, and Emmanuel Lecharny might not fully realize the fabrications they're dealing with.

[1] http://thread.gmane.org/gmane.comp.apache.incubator.general/...

[2] http://groovy.329449.n5.nabble.com/Paris-write-up-tt395560.h...

[3] https://jcp.org/en/jsr/detail?id=241