Banning a party has significant affects on far-right organizations and money-streams. Much of their propaganda will become impossible to finance and any successor parties are automatically banned as well. Fascist voters cannot become disillusioned without a ban. Their beliefs are as solid as a flat-earther or anti-vaxer and only destroying their echo chamber has a chance to take them out.
Not necessarily, bombs that don’t explode usually land on very soft ground - presumably the hole closed itself on top of the bomb right as it buried itself in.