My sentiments about BBEdit's new feature to allow opening files into the same window are similar to John Gruber's. The difference is, I rarely use the Finder for opening files, compared to how often I use a terminal.
I wrote to Bare Bones asking them to add a feature to the bbedit command line program allowing opening of multiple files to a single window, but in the meantime, I ported John's AppleScript to perl (which also allows it to be used, unchanged, with Big Cat).
use Mac::Glue ':all';
my $bbedit = new Mac::Glue 'BBEdit';
my $win = $bbedit->make(new => 'window');
$win->prop('show documents drawer')->set(to => 1);
my $docID = $win->prop(id => document => 1)->get;
my $doc = $bbedit->obj(document => obj_form(formUniqueID, typeLongInteger, $docID));
$bbedit->obj(file => \@ARGV)->open(opening_in => $win);
[Implementation note: by default, Mac::Glue would try to guess that the number in $docID is an index (document 1) instead of an ID (document id 1). The obj_form() syntax, while bulky, makes it explicit.]