This is a strawman. The big AI names aren't making a Pascal's wager type argument around AGI.
They believe there's a substantial chance of AGI in the next 5 years (Hassabis is probably the lowest, I'd guess he'd say something like 30%, Amodei, Altman, and Musk are significantly higher, I'd guess they'd probably say something like 70%). They'd all have much higher probabilities for 10 years (maybe over 90%).
You can disagree with them on probabilities. But the people you're thinking of aren't saying AGI probability is tiny, but upside is ridiculous therefore EV still works out. They're biting the bullet and saying probability is high.