Source below. This is all based on Glassdoor data, so take it with a grain of salt. I would not be surprised if folks with Short positions are manipulating this to an extent, but I also feel that there is a real problem happening as well.
At jobs site Glassdoor, Tesla’s overall company rating fell to 3.2 out of 5.0 stars based on reviews written in the first quarter from a high of 3.6 in 2017, according to historical data compiled by Glassdoor at Reuters’ request. The average rating of the nearly 1 million employers reviewed on the site is 3.4.
In the first quarter, Elon Musk’s CEO approval rating dropped to 52% from 90% in 2017.
Tesla’s “recommend to a friend” rating fell to 49% in the first quarter from a high of 71% two years prior, the Glassdoor data showed.
SOURCE: https://www.autoblog.com/2019/06/10/tesla-employee-satisfaction-ratings-slip/