Here's some management issues OP might be referring to.

- Who is going to provide support, bug fixes, documentation, manuals, etc?

- What happens if you leave? Can our other devs maintain this?

- Did I mention documentation?

- Did you get this approved by the architecture committee?

- Why didn't you follow our process improvement policy?

- We are a Java shop, so can you rewrite it in Java; you know this, so why didn't you write it Java?

There's also people issues with the other devs who may not like OP's tools or want to change their process.