The only way you can avoid loopholes with administration is to enforce such a club to play in the league BELOW the one they are due to play in the following season. So, if you are relegated and then go into administration, then you are still punished. In this case, Leeds would be in League 2 next season as opposed to League 1 as they would have been anyway.
As things stand, Leeds haven't really been punished at all because they are probably going to slash their debts but they will be in the division they would have been in anyway. If anything, they've benefitted from the rule! As somebody else correctly says, relegation on the pitch is a consequence, not a punishment.
The 10 point deduction is no deterrent whatsoever. Automatic relegation is the only choice.