Only professional programmers would consider his code 'bad' or 'sloppy'. But professional programmers have a tendency to over-complicate everything behind twenty layers of abstraction and object-orientated garbage, so they see anything that doesn't do the same as bad code.
The bigger problem is that he used Windows, which is an unforgivable sin.
You make a good point. In most open source projects there are many layers, and code is often developed w/ specific guidelines/structures in mind, etc. It could be argued that the way Satoshi developed the first release of BTC gave somewhat of an easier learning curve for other developers to pickup the project & provide aid; putting that structure & those guidelines into place.
When software is 100% fully developed, it:
1. Takes longer to build, MVP is quicker.
2. Doesn't attract open source developers quite as quickly (if everything is completed, why would developers pick it up). It's these developers which spearhead the project going forward.
Whether this was intentional or not is TBD.