Question
OK, I get it that commercial fruit is hybridized. But (in a very simplistic description) I always assumed tasty, bountiful stock was grafted to hardy root stock. So the seeds should produce tasty bountiful fruit but have the original (presumably) less hardy roots. So there might be some diminution in the tasty bountiful aspects because the tree is using more energy to survive than to produce tasty bountiful fruit, but won't the fruit still taste like the original tasty bountiful fruit?

Answer
Hi Mark,
Thanx for your question.  I have found that many times, the fruit is quite edible and quite good.  What is meant by saying the plant is of lower quality means that certain traits are not stable in hybridized fruit and you may not see those traits from seedlings grown from the hybridized seed.  For instance, a deeper color, a larger fruit, a hardier plant, a plant not prone to certain diseases or pests, a plant able to survive colder or warmer temps, a fruit that is sweeter, less sweet, juicier, keeps longer in shipment, etc.  The warnings are just headsups because many people don't want to waste their time growing from seed and risking a plant or fruit quality that is lower but but not necessarily less edible.  The seeds most often will produce an edible, often very delicious fruit although the "bountiful" part may or may not be true.  The "diminution" you speak of has nothing to do with weak roots but with the instability of a hybrid's genetics.  This is as I understand it.  I am not a trained geneticist or botanist and most of my learning about his comes from high school and Freshman College biology and reading the information provided by various agriculture schools through the major universities on line.

I hope this helps.
Tom