A wise person once said that if you want to get rich and control people, the easiest way is to control people. Some people start religion in order to teach people morals. Other people start religion as a way to stifle the suffering of people. There are many motives for starting religion so it's hard to trust Scientology.
No, the fact that Scientology might be the result of a bar bet does not change my opinion of Scientology. I did not have a particularly positive opinion of Scientology to begin. It seems to be a very controlling, cult-like religion that is highly political. While a few individual beliefs may make sense, it seems to be a highly questionable religion.
Knowing that Scientology might be the result of a bar bet does not change my opinion of this set of beliefs. Scientology seems to me like a way for very smart and savvy people to con rich people out of their money by making promises about self-improvement. Knowing that this belief set may have been the result of a bet fully fits into my conception of it.
It would not surprise me if Scientology was the result of a bar bet. That's honestly exactly what it seems like. All religions appear somewhat ridiculous to those who do not believe in them, but Scientology stands out as exceptionally ridiculous. Learning that it was possibly a result of a drunken bet does not change my opinion of it at all. It was ridiculous and idiotic before, and it's still ridiculous and idiotic.