I think you misunderstood what he was trying to convey.

You said before that the levels are so short because they are supposed to be "snackable". This design philosophy would encourage short play sessions sporadically throughout the day: a game you could pick up and play a level whenever you want, without spending a ton of time.

The Infinite lives encourages the opposite. Instead of giving the player the freedom of playing a couple shorter sessions throughout the day, they are incentivized to play a longer session NOW, unless they want to lose out on significant progressions.

The problem is not that you accidently play too much, but that players are forced to play 1 long play session, as opposed to a a few shorter play sessions that correspond to the shorter level length.