The only problem with singular nouns for table names is that they occasionally conflict with SQL keywords. The canonical example of this is from the TPC-H benchmark which has tables named REGION, NATION, SUPPLIER, CUSTOMER, PART, PARTSUPP, LINEITEM ... AND ORDERS <- plural because ORDER is a SQL keyword.

I like the singular guidance for all the reasons given. I like the consistency guidance. But the real world sometimes gets in the way.