There's a very nice counter argument to the objection of obviousness: if a given invention was obvious to the skilled man at the time of the application, and the invention is useful then why can't you find it in the prior art?
Basically the argument, which I find quite compelling on one level, is that truly obvious stuff is known and citable. Very simply novel inventions can seem obvious once they are presented to you. I found this a lot examining patents - they would often seem obvious but nonetheless be absent entirely from the prior art.
However, to answer some of the proposed solutions there is also the aspect of presentation of the invention to the public domain. That is, even if it were possible for an engineer ("the notional skilled man in the art") to create a close enough solution if they are set to work on a problem this does not provide a reason not to provide some form of patent protection.
The deal is that for disclosure of a workable, industrially applicable invention that a limited monopoly is granted. The monopoly does not only reward but also encourages. Whether others could solve a problem is not necessarily relevant to rewarding those who have addressed it and solved it. Do you see. You want to motivate progress in the relevant arts by rewarding those who solve problems in those arts by the sweat of their brow.
Re ability of patent officers: a judge can watch ice skating and tell you if the people fall over, if their toe-step is dramatic interpretation of the music or them tripping, if their Salchow is wobbly, if their outfits breech regulations, etc., but possibly barely ice skate themselves.
That said in the UK at least there is a good deal of art-specific expertise so much so that the patent office makes a substantial income hiring their examiners out to large companies to do "commercial searches". Mind you when we assessed international searches for the US ones were nearly always useless and had to be re-done (WO patents entering the national phase would sometimes have pre-existing examinations by foreign examiners, usually US or EPO).
>"more useful as engineers"
I don't think people stop being engineers because they become patent officers. That said they probably would be more use to the human race using their skills in a more directly constructive way but this assumes a lot about the world that just isn't going to happen. When there's no greed and everyone works for the greater good then we'll have no need for patent officers.