Here's why:
* Abstract nouns represent concepts, ideas, qualities, or states of being. A quota is a set limit or target, which is a concept, not something you can touch or physically see.
* You can't hold a quota in your hand. You can hold a document with a quota written on it, but the quota itself is a numerical idea.
Examples:
* "The sales team exceeded their quota this month." (The quota is the concept of a set target)
* "The company has a quota for new hires." (Quota represents the target number of hires)
Let me know if you have any other questions!