For an old man nearing his seventies, there's nothing more regrettable than having descendants lost to the outside world.
If Purple Summers really is not a part of the Simonson Family as she claims, then that's fine.
But if...
If she truly is the child Meredith Richards bore for Christopher Simonson, Old Master Simonson would probably never be able to let go until his dying breath.
Christopher was his only son, and not having his lineage continue would be the greatest sorrow for the old man.
In the study, Christopher remained silent throughout; he could not relax either.
Purple Summers publicly declared herself unrelated to the Simonson Family, which meant that, whether there was a blood relation or not, she could no longer return to the Simonson Family.
Otherwise, it would be seen as going back on her word, and the mockery and insults would come down on her a hundredfold, a thousandfold; the Simonson Family would not escape unscathed.