On the site in general, sure. But in the investors thread?
Investors should never, ever, consider themselves 'fans'. I'm sure kodak had a lot of investors who were fans. I'm absolutely obsessed with tesla and LOVE my car! and am definitely a fan most of the time, but as in investor, I try to wear a different hat. Constructive criticism of the company is valuable.
Elon admits he makes mistakes (overengineering the model X, over-automating during early model 3 ramp up etc). He probably knows he makes mistakes with tweets too. Its fair for us to spot those mistakes and criticize bad choices.