How do you terminate the CUDA kernel when a bounds violation is encountered by a single thread? I don't think the CUDA API exposes a mechanism to do that safely.
You can emit `trap` or `exit` in the PTX code (although that has exposed many bugs in the PTX assembler because it does not expect that kind of often divergent control flow). But even if you'd just have the kernel return and otherwise produce invalid results, the fact that you can then report a bounds error instead of silently corrupting data and/or generating a fatal ERROR_ILLEGAL_ACCESS (requiring an application restart) is a significant usability improvement.