No, they just don't want to insure high risk drivers. Like all other insurance companies. If they didn't want to be an insurance company then they would give good rates to high risk drivers and soon go out of business. To be clear, Tesla does not necessarily think your driving got any worse, it's their assessment of your risk that changed.
I'm not saying you're a bad driver. For all I know you may be the safest driver on the face of the Earth. But all insurance companies set their rates based on risk. If you drive at night a lot or if you get a lower safety score, then statistically you are more likely to be in an accident and your rates will go up accordingly.
What you're complaining about is the reason Tesla's insurance model is brilliant. They will shed high risk drivers to other companies that have less accurate risk assessments. This is bad for the other companies and good for Tesla. At the same time Tesla can attract low risk drivers by offering lower rates which is also good for Tesla and bad for the others. The other companies will have to start raising their rates which could be the beginning of a death spiral because more good drivers will leave and only the higher risk drivers will stay.
I'm sorry that you got upset because your Tesla insurance rate rose dramatic. Being upset by that is understandable. But it's not a good excuse to throw logic out the window and claim Tesla doesn't want to be an insurance company because they set their rates according to risk.