Why do Table controls in Base split underlying datetime fields into two separate columns?

A table control in a Base form splits underlying datetime fields into two columns (at least when connected to MySQL, I haven’t tried with the native format).

The values appear as (for example):

fieldName
12/09/2008 13:54:02

in a table or query result, but as:

fieldName (date)
12/09/2009

and

fieldName (time)
13:54:02

in a form/subform table control. I presume this isn’t a bug but rather deliberate behaviour. If so, what purpose does this serve? It seems to me to do more harm than good - what do you do if you want the date + time to appear together?

Also, I don’t quite understand the reasoning behind Base’s subform architecture. Unless this is buggy in v4.3.3.2 (and several prior versions [on Ubuntu]) subforms appear only as part of the reference model in the form navigator and do not appear to be contained within a bounded area - either do their fields - unless a table control is used. What purpose is served by the ability to add subform fields to a master form without any visual distinction if not “designed in” by the user? There being no bounded area, and hence no “continuous forms” option as in MS Access, the table control providing the equivalent of Access’s “datasheet” view, it seems a little loose and liable to confuse - have I missed the point somewhere?

Edit:

A little research suggests there is no “datetime” format as such in HSQLDB, only timestamp, date and time:
http://hsqldb.org/doc/guide/sqlgeneral-chapt.html#sgc_datetime_types

…if this is the issue, has there been a decision not to coerce/degrade a MySQL “datetime” field to an HSQLDB “timestamp” field - wouldn’t that be better than separate date and time values?