#bekind didn't last long then!
This all comes off very entitled and arrogant. In 2020 there are numerous online ways to share your advice, like setting up a youtube channel or posting recipes on instagram. Jamie has a track record of making good TV, he also is known for his work in various social causes and creates appealing food. Advertisers and the TV production company know that he is a well known figure that has a big chance of people viewing, and the public has the comfort of a familiar, positive face.
Rather than recipes being about meeting pounds or pence requirements, it should be about teaching substitutions, pantry meals and making use of limited ingredients be they both fresh and store cupboard etc. Also, every decade has had some form of home/budget cook "face" or author, and you could argue traditional UK fayre based on oats, barley, potatoes etc has always been frugal.
Think Nigel Slater would have been good for this role, he's very soothing and creates good simple recipes, but he isn't, and it doesn't mean Jamie isn't appropriate just based on personal bias. Sending hate to a guy because of a missed job, when anyone can literally start filming in their own kitchen and monetise it today..... really.