So if you built a fence around Switzerland, how would they feel?
Now there's a thought. I'm honestly a bit scared to think about the number of Swiss that might be happy about that...
The problem with the plan is of course that, as mentioned, Switzerland is worth controlling for one major reason: Transit through the Alps. Just locking the Swiss in won't give you that, and t's not like we were a threat that must be contained. That time has gone for a couple hundred years now.
On the other hand, upholding the current standard of living in Switzerland is utterly impossible without Europe around it, and most Swiss have become rather attached to that. So on the face of it, they would not be happy at all. But at least Blocher could finally shut up, so I guess there's a bright side to everything.