On: Java at Alibaba [pdf]

[tuyguntn]

For non-experts in this field could you please explain why its scary if it works great for their use cases?

[titzer → tuyguntn]

Putting it in the heap would generally be safer, as there are fewer special cases to worry about in the garbage collector. Making a copy of the stack and managing it "manually" probably means a lot of special scanning logic in the GC.