It was a time-gated, 2 year ban. It wasn't lifted 'just because.'
During the period that they were banned, they formed a shell party, the National Socialist Freedom Movement, which won a stunning 6%, followed by 3% of the vote (In the two 1924 elections). After the ban was lifted, the next election was in 1928, where they won 2.8% of the vote. Much good that ban did them, eh?
I'm not sure how your point follows from the facts.
