Here's why:
* "Junk" usually refers to something worthless or discarded. Compound words often combine words with related meanings.
* It's unlikely to be paired with a word that creates a positive meaning.
If you're looking for a word with a similar meaning, consider:
* Junk drawer: A drawer in a house where miscellaneous items are kept.
* Junk food: Food that is high in calories and low in nutritional value.
* Junk mail: Unwanted advertising material sent through the mail.