It's not a bad thing on SSD storage maybe. On spinning platter hard drives, we may have to suffer a head seek time to get each field of the object from a separate record in the separate table. Whereas the fields of a record can be stored close together.
“Future users of large data banks must be
protected from having to know how the data is
organized in the machine (the internal
representation)… Activities of users at
terminals and most application programs
should remain unaffected when the internal
representation of data is changed and even
when some aspects of the external
representation are changed…”
Roll the related data up into materialized views for read performance.