The only way you get money on gittip is by producing something others think is valuable and want to see more of. People are voting with their money, which is infinitely heavier than voting with HN comments.
Standups have a common failure mode where they become about justifying yesterday's time instead of serving their most important functions- distributing knowledge and highlighting blocking factors.
Reducing payment friction and user buy-in to the economy increases conversion. FB gets a legit way to profit off the apps on their platform and the apps benefit as well. Is there a downside I'm not seeing?