If you don't write favorably about Apple, then they don't invite you to the press releases. So their hands are no cleaner, just far more transparent and public.
The ones that don't get invited are those that buys stolen goods to be able to show off unannounced products.
2. You rarely hear about journalists getting blacklisted from events because a. the general public rarely cares or b. if they do they call the journalist, a 'whiner'.