I decided to fix reflector in this way because the invalid metadata stream trick is not a particularly strong protection. If someone else wrote a tool like reflector it would be easy for them to work around the invalid metadata stream. In that way, it was the right thing to do.
We will be focusing more on features which provide more genuine protection, by actually throwing away unnecessary information (eg obfuscation), complicating the assembly (eg control flow obfuscation), or by protecting the assembly from modification (eg references dynamic proxy).
I for one prefer to see these real protection features in action in reflector to know that the obfuscator is really doing a good job.
Hope that answers your question,
Red Gate .NET Tools