Not only that, but a central theme in the runup to Brexit was improved border & immigration control. This is something which EEA members don't enjoy themselves, both via Schengen and the EEA's bilateral work permits. Hence, Brexit voters were sold a best-of-all-possible-worlds scenario where the UK would somehow manage to land an EEA style trade deal without literally any of its possible downsides. That seems optimistic to the point of naivete.
My guess is that by EEA you refer to those members that are not already part of the EU, although technically the EEA includes both EU members and countries with a special agreement.
People aren't laughing at the UK for leaving the EU per se. but for the insane and terribly thought out chain of blunders that led to them taking that leap.
At the same time, through the EEA Norway is much closer associated to the EU than the Brexit crowd wants the UK to be. Including e.g. accepting Schengen which the UK didn't participate in even as a member of the EU.
I want also to point out that this would not have happened if Norway had been in the EU already in 2010 because China would not risk trade with all of the EU because of such a small incident.
These aren't necessarily mutually exclusive. Public sentiment has historically leaned towards EU skepticism, something which hasn't been helped by witnessing the EU's broad managerial incompetence (and occasionally petty vindictiveness) on everything from Greece to Brexit.