Thr figures don't reflect reality of life.
Start with the increase. £18600 to £29000. Far to much of an increase in one hit.
Let's then talk about financial situation. Someone who owns a home, no debt, has minimal outgoings and hss a pension/salary of, say, £20000 can no longer bring their spouse to UK to live together.
However, someone with a mortgage, car loan, credit card debt, overdraft, home improvements loan, etc, with a salary of £29000 can live with their spouse in UK.
More than likely the person in my first example will be more comfortable financially.
Also, one who already has a spouse here on a settlement visa or FLR only needs a salary of £18600.