I heard a lot of people saying that it is a bad practice to use IoC.Resolve(), but I never heard a good reason why (if it's all about testing than you can just mock the container, and you're done).

now the advantages of using Resolve instead of Constructor Injection is that you don't need to create classes that have 5 parameters in the constructor, and whenever you are going to create a instance of that class you're not gonna need to provide it with anything