Maybe they want their pilots to have something in common with their customers.
If you take a look at the salary figures, keeping in mind that only 36,500 Euros and 4,200 Euros for working an extra six days are taxable. Run the numbers through a UK tax calculating website. You'll find if you work the extra six days they offer, the after tax compensation including the 70 Euros non-taxable per diem amounts to over £40K sterling.
I doubt that CTC had the capacity to serve NetJets, so the best modular option was off the table. That left Oxford and Cabair as the UK tax benefits are dependent on a UK FTO and bank. They could have gone with FTE, but that probably would have eliminated the UK tax relief and made it more costly.
Ultimately though, you should choose it only because you want to fly private jets, not because the compensation is better than many other tagging and mentoring schemes.