Microsoft doesn't just choose not to release source code; they send takedown notices to projects that redistribute Microsoft's proprietary software (e.g. Ninjutsu OS). They also put clauses in the EULA for Windows to disallow reverse engineering and certain kinds of remote access (something related to if you change who has access too frequently).
Microsoft takes extra effort to prevent people from sharing or modifying Microsoft software, in order to make more money.
Microsoft doesn't just choose not to release source code; they send takedown notices to projects that redistribute Microsoft's proprietary software (e.g. Ninjutsu OS). They also put clauses in the EULA for Windows to disallow reverse engineering and certain kinds of remote access (something related to if you change who has access too frequently).
Microsoft takes extra effort to prevent people from sharing or modifying Microsoft software, in order to make more money.