But this also proves something. From what you've written you knew you were doing something that was wrong. As one example:
"We sold worthless stuff trying to pursued (sic) them into using it over much better and more established companies"
But you had to earn a living so you did that. Now I don't know what your particular situation was or how badly you needed the job (proverbial relative dying of cancer or you would be homeless?) but it might be the same premise that the people running the business operate under. Everybody of course draws the line at a different point in terms of the "harm" they are willing to do. They feel that what they do is ok or possibly de-minimis but what someone else is doing on a larger scale (a guy who did what you did for 20 years or owned the business) is "bad".
I'm curious (and not being judgmental that you worked there as we all have different lines) why you kept that job when you saw what they were doing?