The central issue with electronic voting is that it's opaque to observers. You can't guarantee vote privacy and monitor the counting process at the same time in electronics. I find that problem alone should mean no electronic voting should be used at scale.

Further, vote privacy is threatened at the client side. The fact that they specifically exclude client vulnerabilities is telling: "... known and accepted characteristics of the system will however not be accepted. Such “issues” include: Any operation compromising the vote privacy on the client-side (e.g. browser extension);" They even met "issues" in quotes, even tough these are a common attack vector. They are real and dangerous.

It's common in Switzerland to vote by mail, so there's the possibility that people get pressured into voting in a certain way by their relatives. But the scale is very different when people must expose their voting preferences to a machine they already know watches them.