It is known that an API is used by 1xbit where it is possible to cheat via table tennis, due to the delay present on the site. Most sites have different APIs, so they are less or not affected by that. There are even players who want to buy up accounts of 1xbit that are loss-making so that they can happily continue cheating there. There have been several posts in the forum about this. I'm sure some of these players on the forum have been cheating and complaining about not getting paid.
I acknowledge the fact that there are several 1xbit gamblers who successfully/unsuccessfully scammed the site through various illegal strategies like the table tennis strategy that you mentioned.
However, this doesn't imply that all the victims are scammers. Many of these victims gambled in popular markets(Soccer match winner etc) where it's very difficult to cheat.
Also, this is like the n'th time that I have reiterated some of these points to be honest.