> There was a time when people wanted to dig tunnels with nukes
The article seems to be about mining rather than tunnelling.
And the issue with the idea being? We also dig using explosives, there isn't an in-principle problem. Reading the wiki article it looks like the yields were excessive, but at the end of the day mining involves the use of things that go boom. It is easy to imagine small nukes having a place in the industry.
>And the issue with the idea being?
See the 'rationale' section of the article. The point of it was to rebrand nuclear weapons as multi-use 'peaceful' tools and drive acceptance for nuclear weapons programs. Which was a pretty standard tactic of military projects during the cold war.
The more available they are, the more likely they are to be used on humans.