This is right. The other science topics mentioned have longer timescales (hours or days), so surveys with smaller fields of view but bigger light collecting power are better at finding these events.

For exoplanet transits, though, you're interested in frequent time sampling to catch and model the passage of the planet in front of the star, so sampling all the bright stars in the sky every few minutes is a great way to do this. It also explains the high Arctic observing site (lots of stars that never set and can be observed for months at a time).