The primary one for ecommerce stores is that it would be difficult, if not impossible, to maintain the HTML, beyond a few dozen pages, for a complete site.
In fact, since the early days of the Internet, people have used programs to help generate code for websites.
A visitor navigates to a page in her browser.
All of this happens in less than a second, ideally.
require 'active record'
Setup the database
ActiveRecord::Base.establish connection YAML::load File.read "database.yml"
create table :products do table
table.column :name, :string
table.column :price, :decimal
table.column :description, :text
end unless table exists?
That is an increasingly viable option for companies that want to use a specific platform but still need to customize, say, 10 percent of it.