Andy its design compromise which every engineering design has to do.
If you want decent cooling you go twin fan huge ducted heat sinks. This doesn't work well with the style department.
But I would agree about the quality side of things. There are some things that are very well made but others are lacking.
But controlling heat by dropping the performance is perfectly acceptable. I no I wouldn't advise fiddling with as you can do an Acer and cook the innards resulting in a very short service life.
If you want a machine which runs cool what ever the load you have to go for something like a ASUS ROG with its twin fans. But you have to sacrifice portability, the thing is 5kg. And also the slim line style that apple users seem to want.