The real problem with TG's rules is that they amount to double-padlocking one door while leaving another wide open.
There are two things that TG, ultimately, can do nothing about: 1) the code for the games (at least arcade games) is stored on EEPROMS, which are a removable/rewritable medium that can be altered with zero physical evidence (so showing the board/ROMs accomplishes exactly nothing), and 2) a video recording can be doctored in a way that is not detectable.
(Our live streams are actually more secure than recordings for TG, in the sense that we have live witnesses with whom we interact.)
As for the kits, nobody has ever suggested, much less demonstrated, that the D2K or high score save kits alter the gameplay in any way. If they did, the issue either would have been spotted by now, or is so incredibly subtle that it makes no difference anyway.
But again, the "no kit" thing is another case of locking the one door while leaving the other hanging open.
I have never understood the fact that world class players who have proven themselves time and time again in a live setting are considered to be cheaters... Steve and Billy are known to be great DK players, why in the hell would they cheat? It literally makes no sense.
I'm just gonna say this: the Billy who showed up at the last two Kong Offs did not show any evidence of being a Billy who could play out a 1.1M game at will (or play at 1.1 pace at all).
Yet we have three world record submissions in which he supposedly did so.
One finds, upon investigation, that these games were all "direct video feeds" from the game PCB, containing neither audio nor Billy, (which would never be accepted from any other player), the latter two performances were refereed by one of his best friends, and all three occurred in a context where there was oodles of motive for both Billy and TG to manufacture a new DK world record (during the filming of KoK, just after the movie's release, and the week before Billy's enshrinement in the Video Game Hall of Fame).
So, there's that...