It's not the guns. Switzerland has as many guns as the US and had 3 mass-shootings in 100 years.

[bronxiteforever]

27. This article is outdated. Swiss voted for gun control

In May, 2019.
Gun crazy' Switzerland votes in EU-aligned firearms control
France 24
Latest update : 19/05/2019 - 17:27

Swiss voters agreed this Sunday to tighten its gun laws and meet EU’s demands, according to final referendum results. The wealthy Alpine nation is the world’s 16th country in terms of civilian firearms possession, but has rarely seen mass shootings.

Switzerland’s public broadcaster RTS reported 63.7% of voters nationwide agreed on Sunday to toughen its laws on firearms possession in order to bring it in line with the new European Union legislation on the matter, citing final results.

Also in article
Although Switzerland has a low level of mass shootings, it has one of the highest suicide rates by firearms in Europe. Its rate is three times superior to the European average, according to the Swiss television RTS, and reportedly half of Swiss young men who commit suicide use a firearm -- a record for Europe.

https://www.france24.com/en/20190519-switzerland-guns-eu-aligned-firearms-control-vote

The Swiss passed this to stay in the EU but I think it clarifies the new Swiss position. The business insider article was from 2018.