You've brought up a very valid point
You've brought up a very valid point. I've been a computer consultant and troubleshooter for more than 10 years now, and the poor quality of the cheap computers being offered today disgusts me. The ways that the manufacturers cut corners to get the prices down severely compromise the performance and useful lives of these systems. On-board graphics controllers are the worst offenders, but so are poor-quality hard and optical drives and wimpy, underpowered power supplies. Moreover, the ventilation in those small cases is dreadful.
With desktop computers, for years, the rule of thumb has been that you need to spend about $1,200 for a good-quality system, and that doesn't include a monitor or peripherals such as a printer. With laptops, the cost is probably even higher. I build my own desktop systems, and I've only come across one laptop that could outperform them. That laptop, a Lenovo, cost my client $2,500.
I don't own a Mac, but I would consider buying one if I could afford and justify it. If you're going to compare the cost of a Mac with that of a PC, then you should compare it with an equivalent-quality PC.