It is clear that NATS are trying to attract a younger person to the ATCO job. That's understandable because they have more useful years left. With many ATCOs taking retirement in their early 50's - an 18 or 20 year old is going to be more productive than a 30 year old.
OK, the proposed salray isn't great, but for someone just out of 6th form it's not too bad. The college course is dramatically shorter than it used to be, so depending on discipline and unit, you can be out of there in 6 months and valid within another 9. Just over a year and you're on a decent pay scale. It's not even that hard. It's nowhere near as academic as any college or university course I have attended. The only stress is the practical summatives and they are no more nerve wracking than any other exam (unless you are particularly dodgy).
As a concession, maybe those streamed for area or London airports should be on a higher wage to start with?! because of the extra time to validation and the higher banding of those units.
£10k is not a good wage for a career change, but it is clear from this offer that NATS don't really care about attracting that type of applicant anymore.