I thought I was the weirdo for thinking tomatoes on burgers didn't add any flavor. I love flavorful tomatoes everywhere else, generally, but the kind used on burgers are like mushy water.
You're not alone. I've never liked tomato slice on burgers, always ask to remove if present. Makes the burger wet and slushy for no benefit. Partial to a slice of beetroot as a substitute.
(Hopefully you didn't establish this throwaway account to confess your controversial tomato opinions.)
They want the burgers to taste the same all over the place. A shame because here in south western Ontario we have amazing tomatoes. I eat at least one a day just sliced with a bit of salt.
I'm not convinced this is the case: Why would you choose lesser tomatoes for this?
I'm more inclined to think that modern "grocery store" tomatoes are generally tomatoes that ship well while still fresh. Anything else means that tomatoes on burgers would not only be seasonal, but regulated to the sorts of places tomatoes can be shipped well from the farms.
I'm not even sure how you eat a good one daily, honestly. I've always lived in places with winter, and the tomatoes tend to lose any worth (cherry tomatoes might save you though). I used to grow or buy decent ones during the summer, but moved further north and that went away.
I think a lot of supermarket fruit and veg is picked underripe, and then ripening is induced in a controlled environment in some warehouse a few hours before it's sent to the shops, so that it's "perfectly" ripe as it's placed on display for sale.