Distribution of the source code, modified or unmodified, would not be considered competition. On the contrary, it is an explicitly granted right. So, for example, forking on GitHub is allowed.
Distribution License
The licensor grants you an additional copyright license to distribute copies of the software. Your license to distribute covers distributing the software with changes and new works permitted by Changes and New Works License.
> Any purpose is a permitted purpose, except for providing any product that competes with the software or any product the licensor or any of its affiliates provides using the software.
> Goods and services compete even when provided free of charge. If you market a product as a practical substitute for the software or another product, it definitely competes.
If I use your software and find a bug, I am prohibited from hosting a fork with a fix for the bug on Github as it would clearly be a practical substitute for the original.