As a rule of thumb, people should generally avoid going through message boards and the like after any big reveal of hardware and software. It's now become a bloodbath of fanboys going at each other. They'll just take any piece of (or absence of) information and use it as fuel for their petty arguments. Seriously, who the hell cares what the PS4 will look like? It's going to be a big, bulky black rectangle - like the PS2 and PS3. Will its shape affect purchasing decisions? Not unless it's the size of my PC tower. If you want to think about reasons why it wasn't at the event, consider maybe that Sony wishes to show off the actual production model and not a prototype or mockup and the production models weren't ready by February 20. Maybe they want to avoid a silver PS3 + boomerang controller situation.
When Microsoft shows off Durango come April (if rumours are to be believed), you can bet your ass that these vocal minorities will come out again and start nitpicking every little detail about it too.
Do their opinions really matter? Will their cries of disappointment and outrage alter the direction of where these consoles are headed? Slim yes. Most probably no. Companies listen to dollars and statistics - your whining doesn't change anything.