The cabbie gave Sherlock a choice because he knew he could only beat him by playing the game; he was smart in that he knew how to play him. But he may have forced the other victims to take the pills by threatening them, even though he says otherwise: for him, it’s not only about winning or outliving his victims, it’s about getting money for his kids. Plus, the victims don’t look like they have much hope left in them when we see them crying. This theory is not canon, but do you think it’s viable?
Er… yes and no.
I mean, I think it actually is canon that the cabbie forced the serial suicide victims to take the pills by threatening them.
Jeff basically admitted as much. Sherlock was the only one to realize the gun was a fake. All the other victims figured a 50:50 chance with the pills was better than a guarantee of being shot in the head.
But I think for Jeff the whole thing really did have a lot to do with proving he was clever and having the most fun he could with an aneurysm. It wasn’t only about getting money for his kids. Why? Well, for one thing, the sponsorship of his kids wasn’t part of the unaired pilot episode that told the same story. The original idea was that the whole thing seemed plausible enough without the kids as motivation.