As the in-(my)-house expert on making sandwiches with tomatoes in them, allow me to pass profound comment on this new fruit-vegetable-bastard-child:
A little bit of background might be useful here.
Being too cheap and lazy to hire a cook, the domestic arrangement for sustenance translates into me being the maker of morning meals, better known as the Breakfast Bandit. This worked for me, what with my prior expertise in obscure cuisines such as instant noodles (no, I am not a brand slave - I will not call it 'Maggi', even though that's all we use) and Marie-biscuits-with-cheese-and-ketchup.
However, the combination of a sudden interest in fitness and one-too-many listenings to Sir Mix-A-Lot hammered home the reality that all items mentioned above had to be abandoned in favour of what society at large considers 'healthier' alternatives. Simplicity, taste and cost were still pretty high on the list of priorities, which ruled out karela juice and assorted 'organic' produce.
After a few false starts (warning to reader(s): 'dinner leftovers' as a suggestion for breakfast to the ol' ball-and-chain might get you slapped. Or kicked in unpretty places. I'm not saying this happened. Just a warning.), we finally zero'ed in on a solution towards the end of 2009, which is still going strong: Tomato slices on toasted bread-and-butter with the occasional embellishment in the form of cheese spread or chutney. In short, tomato sandwiches.
Now let's look at the role of tomatoes on sandwiches.
Tomatoes aren't meant to have a 'taste' - they're basically water and random red pulp, that is ideal for absorbing anything. The purpose of a tomato on a sandwich is not to impart flavour - the humble tomato slice is a medium for masala, a carrier of condiments, a purveyor of pepper-salt. It is the perfect seasoning delivery mechanism.
Juiciness is, ergo, a necessary property of the tomato, as part of its duties as a seasoning delivery mechanism. But I wouldn't stop here. In fact, I even assert that LEAKINESS is an integral part of a tomato in its role as a slice on bread! In fairness to the article, I do mean toasted bread here, but who in their right mind makes a sandwich without toasting the bread first? I scoff in their general direction.
A reasonably toasted slice of bread should be browned. Toasted bread, however, has this weird property wherein it gets harder with time, if left in dry company. This results in some not-infrequent teeth-gnashing and quite a bit of cursing when attempting to consume such a (shoddily prepared) sandwich.
In summary, the perfect tomato sandwich consists of well-toasted slices of bread, on which the tomato slices have been placed. The requisite seasoning is then sprinkled, sprayed, spritzed or slathered atop these valuable vegetable vehicles (fruit, technically, but that destroys my alliteration, so…). The leakiness of the tomatoes then, over time, ensures that the flavours of the seasoning are well-distributed across the surface of the bread, while still managing to concentrate the total awesomeness of the sandwich right at the centre. This would not be possible if the tomatoes were not leaky.
TL;DR version: Non-leaky tomatoes => non-awesome sandwiches
Consequently, Tesco's tomatoes can, IMHO, go jump their genetically modified (my baseless accusation, not The Guardian's), non-leaky selves off their shelves and onto sandwich Luddites' bread-slices all they want - as long as they stay away from mine.
Note: This does not absolve tomatoes of their two other key requirements.