I agree.
The '1' was an example of what you could do.
A better houserule would be to introduce failure results based on the amount you miss the DC by.
Example:
missed by 5: Lock damaged. -1 on open lock checks with this lock
missed by 10: Lockpicks damaged. -1 on open lock checks with these lockpicks
missed by 15: lock ruined. can't be opened, not even with original keys.
missed by 20: lockpicks ruined.
Note that this would disallow take 20, since the penalties (implied when taking 20) would ruin your check, unless your bonus is high enough to 'take 1' and succeed on the lockpick check.
On the other hand, if you would introduce (non resetting) traps on failures, you can take 20, but the trap will go off.
Edit:
because you can't use Take 20 with rolls that have negative effects if you fail
No, you CAN take 20 on rolls that have negative effects if you fail, but the negative effects occur. In the particular result of the negative effect influencing the result, you are correct