I'm sorry to hear about your experience, but I don't think that it represents the nation at large. Here is why...
According to the most recent census data I could find (2015), there are approx. 27M businesses in the US[1]. Assuming half those businesses are wage thieves, that would mean 13.5M businesses are currently in violation of the the law. The DOL can place a $10k sanction on the business owner for a first infraction[2]. This would then mean that the US gov't stands to make $135B by placing sanctions on these businesses. To catch each business, let's say it costs the DOL $2500/business. After looking into each and every business, they would run a total of $67.5B. Now they have made $67.5B after all expenses have been made. To put that in perspective, the US gov't has put aside $9.7B for the DOL in 2018[3]. As you might figure on your own, $67.5B is nearly 7 (6.9587628865979381443298969072165 if you want to be super accurate) times the DOL's 2018 budget. Now if you mean to tell me that the gov't is going to leave that sort of money on the table, then you and I need to figure out how we benefit from this.
You might well be thinking something along the lines of "The gov't is inefficient, etc. There is no way they could reclaim all that." You're right this is definitely a perfect world scenario, but even if they could only claim 1%. That still makes up a 10th of next years DOL budget. For the gov't , these numbers only get better as more businesses commit these crimes.
Now we have to look at this from the perspective of a business. Again there is only roughly 27M in the US. To make it fiscally responsible to take the $10k bet of sorts the business must save at least $10k/violation, obviously. For the sake of this argument let's say violations are handed out per person per month. ((404)7.25)+(((3024)-(404))(7.251.5)) = $7250, that is how much you make at minimum wage including overtime... If you worked literally every hour of every day for a month (30 days, technically). So if we assume the business thinks a person is going to report the violation, they are better off just paying minimum wage upfront. Let's reel this in a bit and say you work 40/wk/mo in overtime. ((404)7.25)+((404)(7.25*1.5)) = $2900. So now the business definitely comes out ahead. They would risk $7000 by trying to save, what, $1000? Remember, this is an extreme case, not everyone is going to work 80 hours a week. Even if a business isn't more likely to hire another person to cover your 40 hours of overtime a week, they can only save $580/mo compared to the $10k/violation.
I know that there are businesses that will literally do anything under the sun to make a buck, but I find it hard to believe that even half of businesses would go against some of the math above.
[1]: https://www.census.gov/data/tables/2015/econ/susb/2015-susb-...
[2]: https://webapps.dol.gov/elaws/elg/minwage.htm#Penalites
[3]: https://www.dol.gov/sites/default/files/FY2018BIB_0.pdf