Some are obvious next steps, these also deserve no protection
Some involve design (in a non-engineering sense), for these we have copyright
Some ideas take decades to develop, these deserve protection
Some idea take billions of pounds to develop, these deserve protection
Who is to judge wich category my idea falls in?
Because if they weren't protected nobody would develop them.
Imagine if Ford, Cheverolet, Cat, etc. etc. all had to develop their own unique way of operating their vehicles (because the way we operate them now is covered by patents), that would seriously hurt our choice in vehicles and not to mention driving up the costs significantly across the entire automotive industry.
The same principles apply with the iPad and the Galaxy Tab.
If SamSung is forced to do things differently, the price will go up and usuability will go down. And it's not like they are hurting iPad sales.
So, at what cost do we want to keep protecting ideas?