Iceberg lettuce is the most pointless waste of time and money in the entire agricultural industry.
You are absolutely correct in your assessment of vegetable quality. Everything is bred for transportability, appearance, and shelf life, then flavor and nutrition go out the window.
It's exactly the same story as the Red Delicious apple. They were bred to be very red, not at all sour, and to not bruise too easily. So they look good, but taste like garbage.
I have noticed the same devolution in watermelons. You used to be able to get huge, arm-filling watermelons, juicy and sweet, but shot through with big black seeds. Now at the supermarket they're all seedless, nearly flavorless, and small.
Same with strawberries. They used to be small, but intensely flavored, and ranging from very sweet to slightly sour. Now you can find them as big as your clenched fist, but then bite into one, and it just tastes like dirty water.
I don't buy food to look at it. It seems like the greatest minds of the last agricultural generation have all been wasted on making foods look like they'll taste good, and look like they're worth the money, but then become a total disappointment to your tongue.