There's no denying their effectiveness in this example, but then the context was the UK was fighting a conflict halfway across the world and without air superiority. Take away either of those elements and the Super Etendards were likely to have been obliterated long before their Exocets were within range.
Furthermore, waiting would have meant the islands would have entered Antartic winter shortly after invasion, giving them many months to dig in and prepare for UK Task Force landings.
There where probably career officers raising all the issues you did and more but it didn’t matter.
It’s interesting to speculate what thatcher would have done had the Argentines managed to sink enough ships to end the first Task Force, we where already fighting at our limits (which showed just how poor our equipment and spending was, lions lead by donkeys still applied), force project is hard, force projection for a 2nd rate power (if we class superpowers as 1st rate) at best is ridiculously hard.
To be fair, Israel also advised Argentina on air-to-sea surface attack tactics that proved to be seriously good.