That's because their chief weapon is surprise... surprise and fear.

Although, and I haven't watched the video, usually when people are singing the praises of the Inquisition, they are usually explicitly not talking about the Spanish Inquisition. Instead, they are talking about the Papal Inquisition, which was a separate institution.

The idea is that, prior to the Papal Inquisition (the professionalization of inquisition), "Heresy" was a charge that was often levied by secular authorities against political enemies, with the "heresy" being a vague charge that could mean anything. The Papacy took that out of their hands, requiring that charges of heresy be investigated and tried by church officials supported by Rome.

Of course, there were definitely problems that the apologists don't talk about. The accused weren't told exactly what they were accused of, nor were they allowed to face their accuser. They are often imprisoned for months with no idea why, expected just to confess to whatever it is they did (which resulted in quite a few unrelated confessions). Torture was often used to extract confessions, and though confessions extracted through torture were not allowed to be used as evidence, they had no problem accepting formal confessions given the following day (based on information gained through torture).

That said, if, not knowing who was accusing, you managed to name your accuser as someone who had beef with you, that was often enough to exonerate you. And if you did confess to heresy, all you had to do was say "I won't do it again", and you were off the hook... the first time. If they had to come back, you were turned over to secular authorities for punishment... and the secular punishment for heresy was burning (on the Continent; in England it was often hanging).

That said, back to the Spanish inquisition, which was a real piece of work, itself. It was under the control of the King, not the Church, and so was just as political as the ad-hoc institutions of the past. And though Jews were officially not under the jurisdiction of the Inquisition (since the Inquisitions mandate was to investigate heresy, and heresy is deviation within a particular religion, not being a totally different religion), Spain had required all their jews to convert or leave, and so Conversos were often targeted for investigation.