I agree, but the trouble is it takes many months for audited accounts to be complete, which is mid-way into the next season, meaning cheats like Forest and Leicester will by then be in the PL enjoying the vast new cash inflows.
To put in perspective:
The bottom club in the PL is now guaranteed...
But they will still gain their ill-gotten gains of 1 years PL money, and 4 years PL parachute money even if they comes straight back down due to the 15 point penalty.
Make it financial penalties in the £10m's on top of a points deduction, should do it.