This is not an error condition per se but is an informational type message. This need to optimize occurs whenever you import data through STEP, IGES, etc. We do not do it on import as this will add additional processing overhead and complication to the import workflow.
Please see this thread for a detailed explanation of why you should consider optimizing imported geometry:
This is not really an error per se. It is a condition in which an imported solid has not been checked for simplicity. Many times when a solid is imported from another format you are left with multiple surfaces where there should be one, or multiple edges that can be combined into one. A good example is a cylinder where the circumfrential surface has been split into two surfaces. This tool simply performs those simplifications to the model to improve performance. As far as I know there is no batch tool, and I don't know why this isn't done during the conversion itself.
I use this out of habit on EVERY imported part. As others have mentioned it helps with future editing.... especially if your into Synch. It will find parallel faces, and other Synch type things. I also usually re-orientate the part so the Synch works too.
What I wish they would do is Automate this more. They should allow for an Import that place the Origin dead smack in the middle of the part so that many faces etc. are ready for editing.