Is 让 more [make] than [let]?
It all depends on the context. The readers would know which meaning of 让 you are referring to, by having the information of the activity is wanted or unwanted, and decide 让 means "make" or "let"

In most case, eating apple is something you like to do, therefore, "让" in "我父母让我吃苹果" should be interpreted as  "let" unless you specify you hate apple

For example: "我父母让我吃苹果，我就假裝牙痛" - "Whenever my parent make me eat apple, I would pretend to have a toothache." 

If you need to make excuse to avoid eating apple, the readers would know you don't like apple and decide "让" means "make" instead of "let"

Similarly:  "我父母(終於肯)让我吃苹果" - "My parent (finally agree to) let me eat apple"

From the words "finally agree to" we know you don't get to eat apple often or it has been a long time since you had one. We can confidently presume  "让" here means "let"