Note: the previous query selected everyone except the frequent borrowers, so people with 0 loans are listed. In the new query people with 0 loans do not appear in the subquery so the where clause 2>= ... evaluated to false!

Note that it makes no difference whether we write 2>= ( select...
or 2>= some (select... or 2>= all (select ...
as the subquery returns 1 value as its result.