Well, I sometimes use convenience food these days simply because I'm too exhausted to cook from scratch (as
medtran49 says above). I'm a full-time carer for my partner who has dementia. And of course of there are some medical issues which can make preparing food really difficult. I recently broke my leg really badly and this affected my lower spine. Frankly, due to intense pain, I couldn't really stand up for more than a few minutes in order to cook.
Anyway, I think what is interesting to me about this thread is an underlying assumption that convenience food is not 'healthy'. To me an omelette is a convenience food. It takes but a few minutes to cook but is nutritious. Here in the UK we are very lucky (or not, depending on your viewpoint!) in terms of ready-made meals. They are not frozen meals but 'ready to cook' and most contain no nasty additives. There are whole large aisles in UK supermarkets devoted to such meals and you can buy a huge variety of cuisines. I actually think that most of these ready meals are better nutritionally than the food many people cook from scratch at home. How is that for a contentious statement!