Have you ever bought a home electronics component, a computer peripheral or portable device only to find out that a cable or accessory that you assume would have come with it does not? It is extremely frustrating occurrence that seems all too common these days. In order to fully utilize what you bought, you are essentially required to purchase more which adds to the cost of the product. Why on earth do companies do this when they known it will just annoy their customers?
Consumers are very sensitive to pricing. It is often the number one factor when a buyer goes into a store and looks at two different products and having to decide which to get. Because of this, manufacturers have an incentive to try and make they products as low cost to produce as possible both to reduce the final retail price but also to try and raise their profits.
There is a secondary effect as retailers also like it when a cable or accessory is missing from a product. This allows them to try and upsell the product. This is especially true of the cables used to attach consumer electronics components where various companies sell overpriced cables with inflated claims about performance. Just avoid these practices and look at affordable and reliable sources of cables such as which has just about any type of cable imaginable for much less than what a retailer would sell them for.
As a consumer, it is important to do research on products carefully. Check to see what comes shipped with a product. Find out if there are things that might be needed. I will give two examples of some instances that might require some extra purchase. The first is the Amazon Kindle Fire HD tablets that do no come with an AC adapter to charge your device from an outlet. This is another $15 you will need to spend to get something that comes with most tablets. The second is many low cost printers that do not feature a USB cable required to plug it into your PC. Many monitors do similar things with certain cable types. In each case, checking the label on the box or the product details can show what is and is not included with the product.