I know what you're saying and it may seem that way, but that is not the case. Maybe you're just being sarcastic.
I don't work in the industry of course, but maybe I can shed some light on this...
Manufacturers and their test/team drivers do research and development. In companies that know what they are doing, there is a some type of process for testing, feedback, product modification and retesting - and this cycle repeats itself during the product development phase, but this can't go on indefinitely. And of course it is not possible to test everything that could possibly be done or happen to a product. At some point the manufacturer has to decide to start production. All of this product development and testing cost money and they have to start recouping their costs to start making a return on their investment (also pay back loans in some cases) to continue staying in business.
After the product goes to market, we all become unofficial product testers/guinea pigs. We use the product and contact the company through official support channels (direct), dealers and distributors (indirect) or unofficial channels like this forum and ask for assistance and/or we complain about a specific issue. Once the information gets back to the manufacturer, they may ask specific questions to better understand our issue (directly or indirectly), to help them make an assessment as to if there is a defect in design, material, workmanship, instruction, etc. Based on number of support calls or complaints about the same issue (or just one incident, it really depends on what it is), they may/will do some research to determine if they need to make a change to the product.
I'm not sure if there is such a thing in the R/C world, but for other things, there are "official" consumer product testers that test specific aspects of a product (or service) and provide their feedback through a formalized process. In this scenario the manufacturer is the primary researcher and the customer is just the guinea pig. In some cases, the customer may do some official/unofficial product modification and testing, and provide their feedback to the manufacturer. I guess some sponsored drivers could be considered official product testers, as I know some that do the latter.
Some companies are better at all of this than others of course and that's what makes the difference between a good world class company/product and a bad company that produces a piece of junk. Some companies are really good at improving their products, while others continue to produce only slightly better products that continue to have issues.
A new company is the most challenged when bringing a new car to market, but it depends on on the experience of the personnel, their product development process, who is doing their testing, how much money they have and the company manufacturing the parts.
.. and of course there are times when a good company starts manufacturing junk.