Why I do not like Struct for PORO (Plain Old Ruby Object) ?

no_struct_for_poro.rb

Customer = Struct.new(:name, :address)

c = Customer.new('john')  # Do not validate construction
c.name                    # => 'john'
c.address                 # => nil

c['name']                 # => 'john'
                          # Extra unneeded API to access your property

c['name'] = 'robert'
c.name = 'emile'          # Public mutability by default  

For an immutable Struct see https://gist.github.com/simcap/622cac189c9cd0f8665d