Should I use MongoDB or a relational database management system for this scenario? I have a different item types, each item has different number of attributes some attributes might contain an arbitrary number of values. For example, a building which has amenities attribute, this attribute has many different possible values a user should be able to select these values for the item Building from a list. Some examples of these values are Balcony, Pet Allowed, WiFi. Another item is Car this car have different attributes like Model, Speed, Class each of them has a single possible value.
In addition to Attributes I have a different nested Categories for each item, for example a Vehicle category, is a parent of Car category which is also a parent of BMW Car category.
As you can see, the second requirement can be modeled easily for a Relational Database but the first one is very hard to model for Non-relational Database like MongoDB. My app will be used by huge number of users, and both categories and attributes are subject to Insert/Update/Delete operations also they may be involved in some reports generation process.

I think about using MongoDB as DBMS, but I'm not sure yet about this decision.
To answer your base question, why not. Value lists are easy to make, child - parent can be made with references. You even mix those two to the single key.