I agree there is an issue revolving around holding down the clap icon, the gratification seems to be lost after a few seconds on any device.
Medium must of considered two things –
1) Clapping after reading a stimulating point
2) Clapping at the end of a post
Both of these options present an opportunity to lengthen the applause but in doing so seems to be taking away the reward of the writer and reader. It would be interesting to see in their research why they chose to give users the option to lengthen applauses. This length may make users focus less on the exciting or useful points they have just read and get lost in watching a counter.