The paralympics includes numerous sports at which it would be unfair to pit non-disabled athletes against paralympians. Running's a lot harder without legs.
But if the olympic movement really believes in all that 'uniting the people of the world' stuff then why don't they have a mixed paralympic/olympic games?
Wheelchair fencing, wheelchair rugby, wheelchair racing; all these would be equally good for able-bodied people. Even blind football, given that the players wear eyemasks, could be open to sighted people.
Target shooting, as I've already made clear, isn't a sport. But if it were then why couldn't it also be a mixed sport? In what way does being in a wheelchair make any odds to your performance? That's not a paralympian achievement, that's just the same shooting but sitting down.
Sure, it'd be unfair to pit blind footballers against the sighted ones, but then the olympics already distinguishes between people on grounds on grounds of physical ability in having separate versions of the same event for men and women.
Athletes with disabilites could be included in the olympics, but aren't. That being so, an argument could be made that the discrete paralympics actually encourages an attitude of separating people with disabilities from the rest of society.
Rather than have two games for paralympians and olympians, let's have just one games, all performance-enhancing substances allowed and even encouraged, then we'd get to the purpose of the Games: see all the world focused as one on what human athleticism can really be.
[NOTE: I can't tell to what degree I'm serious about any of this.]