There is really no reason to assume that a reverse engineering tool that's capable of documentation or diagraming the relationships between tables has anything to do with the fact that you have some saved queries? A view is only some saved SQL query and has NOTHING at all to do with relationships between tables.
A saved SQL query (aka a view) is NOT a table design structure. The creation of a view or the deletion of a view has NO BEARING WHATSOEVER IN ANY MATERIAL WAY in terms of the database structures and relationships you build in a database.
As a result the reason why with an conservative estimate of 1 trillion web pages in existence a Google or Bing search results in ABSOLUTELY NO RESULTS for your question.
In other words your assumption that a database ER diagram is to include a bunch of saved SQL queries is a complete and utter fallacy on your part.
Now you might be asking if such a documentation tool exists, but you actually asked WHY you cannot find any information on this subject and the simple answer is because nobody else on the planet and in fact as far as we know in the galaxy makes the assumption you're making.
being able to "see" them via Access has made me a bit more frustrated.
And it's not clear why you show even more confusion by asking why you can utilize such views in an application development tool such as MS Access?
The simple answer as to why you can see these views using Access is because Access is not a reverse engineering tool. In fact Access is also not a database documentation tool either.
Access is a software development tool that allows you to build applications and CONNECT TO A GIVEN DATABASE SYSTEM. Thus MS Access can use a database such as the native database engine that ships with the product (JET or now called ACE). Access can also connect to Oracle, or something like SQL server.
In ALL these cases without a doubt Access can connect to a SQL view since the tool is designed to CONSUME data from the particular database engine. However consuming data from a particular database system is a MASSIVE AND SPECTACULARLY DIFFERENT PROCESS then using a reverse engineering tool to ascertain the relationships between tables.
The fact that a database system has some relationships between tables, or you have enforced relationships that you wish to diagram has absolutely nothing to do with the process of having something document a bunch of simple SQL queries saved in some place. So all a view really is some saved SQL. You can save SQL in code, in text files, or in the case of Access in with what we called a select query, or in the case of SQL server you can save SQL as views.
However, looking at a bunch of saved SQL queries is an entirely different matter then documentation the existence of relationships between tables in a database. Creating views, delete views has ZERO bearing on those relationships between tables.
In fact we see that MS Access table diagram tool does not have the ability to include views in the table relationships diagraming tool included with the product. So in fact MOST development tools do NOT include views in the overall table ER diagram.
So at the end of the day the likely reason why something like Visio cannot simply consume and utilize a bunch is saved SQL queries is that by design such a tool is not intended for that purpose at all.