In case mentioned in title she/he may implement an ugly feature like this:

c:\>sgen.exe /p /force MyAssembly.dll
Microsoft (R) Xml Serialization support utility
[Microsoft (R) .NET Framework, Version 4.0.30319.33440]
Copyright (C) Microsoft Corporation. All rights reserved.
Assembly 'MyAssembly.dll' does not contain any types that can be serialized using XmlSerializer. Please use /verbose switch for more information.

Okay, let’s do it with /verbose flag:

c:\>sgen.exe /p /force /verbose MyAssembly.dll
Microsoft (R) Xml Serialization support utility
[Microsoft (R) .NET Framework, Version 4.0.30319.33440]
Copyright (C) Microsoft Corporation. All rights reserved.
Assembly 'MyAssembly.dll' does not contain any types that can be serialized using XmlSerializer.

Funny, isn’t it?