The list doesn't have to be prescriptive, it's just a 5 day example.
If smoked salmon is too expensive, smoked mackerel or tinned fish has similar health benefits and is much cheaper. If you don't like porridge, you can have oats or muesli with yogurt and fruit. If you don't like the vegetable they suggest, eat another one.
Agree that there could be better ideas for using up whole packs, but all the recipes were for one person, so anyone feeding more will scale up anyway. Or use a whole small banana instead of half a one.
If you eat bananas, it's not hard to buy an appropriate amount that you think will get eaten within the few days before they go off - all supermarkets and most convenience stores sell them loose and in a variety of pack sizes.
I got the idea for a gorgeous courgette dhal on here, but most people on that thread seem to hate the idea.
It's strange that the sort of food suggested in that article (which was just published by the Guardian - the menu plan originated from the British Dietetic Association) is the sort of normal everyday food (pulses, eggs and vegetables with a small amount of meat and fish) that half the world, many of which are poorer than the average Brit, eats.
But here, good food is seen as a wanky, aspirational, middle class activity 
.