Custom PHP content General Discussion

I'm currently using Drupal for an internal intranet site to deliver php content written outside of the drupal framework. Examples include, start pages and work lists using data from another DB

Essentially we have a custom php content type and the developer and myself just create a node and then use an includes to the php file which we want to use. Our code base is well structured with pages that we want to display in drupal held in there own node folder of each project.

I seem to have read that this is bad practice but there a few reasons why we have kept it this way.

• We don't need drupal specific developers
• We can us things like print and flag in the footer easily (this is a big one) we use flag to let users bookmark useful pages
• We are not dependant on drupal as a delivery method if we need to change.

Why would we change from this model and why is it such bad practice?

Thanks Dan