If players were banned from entering a tournament if their machine was used people would simply not pledge their machines meaning that the comp would be unlikely to run in the first place.
Of the 10 machines used, 6 of them (F14, HS2, RS, TNA, Circus, Robocop) were donated by people who did not enter the competition at all.
CftBL was donated by Flipout (at my request to Matt), and 3 came from me (IMDN & WPT owned by me, AS loaned by Courtney).
I have never owned half of those machines, but know the rules inside out, as I do for the vast majority of JJP, Stern, Williams and Bally games. That is experience built up over many years playing, watching streams, and reading rule sets. The machines were all published beforehand as soon as I had them confirmed, with the exception of Robocop, which was a very late substitution (less than 5 minutes before doors opening) due to Black Jack failing.
The machines were picked based on suitability for competition play, availability (preference given to those machines duplicates were pledged - TNA, Robocop and
CftBL) and the likelihood that they would all stand up to a weekend of hard playing - to suggest that I cheated by putting my own machines in I find distasteful. In fact I find it is generally a disadvantage, as having played a game set up a certain way at home and then setting them up in a different place with different levels and tilt sensitivities the machine plays completely differently. My scores on IMDN were well below par from what I would expect to get at home (to get on the highscore table it needed a score over 2Billion). The same applies to playing a different version of the same game.
How the comp was based on greed is still an argument I don't understand - the prize money is to encourage people from further afield (Europe mainly) to travel and thus increase the appeal of the show. I understand that you are not interested in competition, you have made that perfectly clear on any number of occasions, but many others are - the competition is to appeal to them, if you don't want to enter don't, as many people didn't.