Totally agreed and well said. It can be easy to read too much into something (especially when people are learning how to understand literature in high school), but some level of decision-making, i.e., design, goes into every word.
Nathaniel Hawthorne didn't choose scarlet because it was his favorite color.
Lord of the Flies is also a particularly silly example because the author practically hits the reader over their head with the officer at the end to yell at them, "this is an allegory!"
Nathaniel Hawthorne didn't choose scarlet because it was his favorite color.