In my last project, I was advised that, while writing good code is beneficial in the long run, the cutting edge is all about prototyping fast, finding out what works, and not getting invested in ideas that don't. Now, I am of the opinion that poor software engineering practices cost a price in the long run. Also, frequently code that was never meant for production finds its way onto many other scientists' computers. Personally, I blame it on a lack of experience and general computational education. It's not that hard to add docstrings to python code. Hell, it's easier to use standard modules than to roll your own format parser. I'm regularly able to compress code bases in half by just adhering to the best practices of the language being used. But that doesn't win grants.