You can't be this naive I hope. It's very simple. Nintendo developed a custom USB-C standard which 3rd-party companies reverse-engineered in order to create their docks. Most of them were already bricking the Switch, but after the 5.0 update, Nintendo apparently made some changes to improve the security internally (5.0 was an update mostly for Nintendo and security, not end-users) and then more 3rd-party docks were bricking the Switch. It seems that the new update has exposed the third-party products from bad reverse-engineering, hence why the Switch bricks suddenly increased. Nintendo can't control what those companies do because they were not licensed by Nintendo and they continued to create docks that they were not entirely sure whether it was entirely compliant with the Switch's hardware and power output.

The only thing 5.0 has done is expose the third-party companies that got away with poor reverse-engineering initially, but since now have shown to do a bad job.

Nintendo is in no way responsible for what non-licensed companies sell as Switch docks.