The original question doesn't really bother me, but I'm surprised by the blind faith several on here have shown in relation to the cleaning process.
I'm sure I'm not the only one to have boarded a (BA) flight to find that the aircraft hasn't been cleaned - even those that have sat overnight at their home location.
Oh well, I guess those people who charge past me as soon as the last passenger is off must be ghosts.
Maybe they're not cleaned to the standard you'd like but as someone who works at the airport and sees the cleaners on board numerous times a day, I can assure you every aircraft is cleaned.