Red Class are made overseas, more cheaply, and using more affordable materials. The other classes, and even before BM started color-coding their different lines, have historically been higher-priced, upper-echelon level of knife. While this definitely forged them a reputation of quality, they were obviously missing out on a large portion of the market, low to mid-cost knives for casual users.
So now there's the Red Class. As you've noticed, a lot of these are hard-working, utility based blades, intended for people who don't want to use a more expensive knife and risk destroying it, or would balk at the cost of a Blue Class knife altogether.
In Benchmade's case, the Red Class is a bit of an enigma. Compare BM to Spyderco for example. Spyderco has its host of high quality, higher cost knives, but the bulk of their business is in working knives at half the cost (like the Delica). Many companies are like this. Kershaw has a few high-range knives, but most of their sales come from lower cost Leeks and Scallions. Compared to these companies, Benchmade seems backwards. Their best sellers are double the price of Delicas and Leeks.
This might make an observer cock an eyebrow at the Red Class, but be assured that they're fine knives. They wouldn't have the butterfly on them if they weren't. For the pricepoint, you'd be hard pressed to find a better alternative than a Monochrome or Pika. The fixed blades would easily give Buck's classic hunting knives a run for the money. They use a lot of 440C in the Red Class, which outdoes the AUS6 or AUS8 you'll often see other companies use.
Finally, they're backed by Benchmade's warranty and customer service, which is one of the best in the industry.