Somehow I don't seem to have the same experience as most people in this thread. Sure, homegrown tomatoes and cucumbers taste quite a bit better than what I usually buy at the supermarket, but it certainly isn't perfect vs. inedible.
Possible explanations I can think of:
1. My taste perception is just broken because I am relatively young and have been raised on low-quality produce.
2. My local supermarkets just happen to stock excellent vegetables (I live in Central Europe).
3. There are some extremely high-quality breeds of tomatoes/cucumbers that I have never eaten before.
4. Other people are simply more enthusiastic about vegetable quality and therefore their claims seem exaggerated to me.
First is that some produce really is terrible -- "regular" cheap tomatoes can be utterly flavorless. But on the other hand, a lot of supermarkets stock tomatoes that range from fine to quite excellent, e.g. cherry tomatoes grown in greenhouses sold on the vine.
And second is that people really do exaggerate how great homegrown tomatoes are. There are tomato snobs in the same way there are coffee snobs, whiskey snobs, chocolate snobs, whatever. They insist something is 100x better, when really it's just 1.5x better, because for some reason that's important to them, part of their identity.
Yes, a farmer's-market heirloom tomato is utterly delicious. But store-bought cherry tomatoes on the vine are also super super tasty. Even the ones not on the vine can be really really good. (You can also find really bad ones though, it depends on the store.) I'd go so far as to say they're just different, neither obviously better than the other.
Possible explanations I can think of:
1. My taste perception is just broken because I am relatively young and have been raised on low-quality produce.
2. My local supermarkets just happen to stock excellent vegetables (I live in Central Europe).
3. There are some extremely high-quality breeds of tomatoes/cucumbers that I have never eaten before.
4. Other people are simply more enthusiastic about vegetable quality and therefore their claims seem exaggerated to me.