SharePoint, to GAC, or not to GAC?

It's clear from these questions

When and when-not to install into the GAC?

What are the advantages and disadvantages of using the GAC?

To GAC, or not to GAC?

that it is not recommended to de开发者_如何学编程ploy assemblies to GAC as explained. So, I'm wondering why is the default of SharePoint solutions built using Visual Studio or WSP Builder is to deploy assemblies to GAC?

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Various sharepoint components (besides just the site) won't be able to find it in the bin folder. See this other post for more details.

Does a SharePoint EventReceiver have to be installed in the GAC, and if so do all dependent assemblies have to as well?