I'm sure a few of the programmers work in the industry.
But, I think you have the original codebase to thank. It's been organically grown from what was started with, and it is a credit to the SCP team that it still works, and that they've managed to grow a community around it.
I don't think there is a single person who would call the codebase 'clean' or 'beautiful'. The original team used the words 'horrifying atrocities' to describe the released code.
By all means, I encourage the development of a new codebase, including graphics pipeline, and base filesystems. But you've gotta realise that this community has been brought together by a love of the game (myself, the story is much better than any other game I've come across recently - IMHO) and a desire to improve the engine and the available campaigns and missions.
Your level of experience will help with developing a new engine, however, we're not all professionals, and working on this game engine has taught some people rather a lot. I look forward to seeing what you can bring to the team.