Hoa Loranger elegantly strikes down the “users don’t like to click” myth:

Readers treat clicks like currency: they don’t mind spending it if the click is worthwhile and has value. However, resentment ensues when a click is considered a wasted effort; it doesn’t take many wasted clicks to escalate people’s reaction to full-blown defiance.

By the way, if you’re thinking about designing an accordion, you might want to read the rest of her article first.