I know more people who got tickets in the various pre-sales for the UK shows than the General Sale, so there were plenty of tickets available and not all at skyhigh prices either.
At the end of the day it's the luck of the draw but certainly pre-sales work as far as i'm concerned - I've seen Mccartney three times in the UK so far (with a four show in December) and have never had any issues getting tickets for any of the shows.
Also, I've never paid more than £80 for a McCartney show so these tickets certainly aren't "beyond the reach of ordinary working people".