What's the rush?

What's the obsession about getting young toddlers out of their crib and sleeping in a toddler bed? Why are some parents so rushed? I know my LO is safer in her crib and I'll let her use it until it's obvious that she needs a change. I understand the desire to potty train early because of how expensive diapers are but I really don't understand the crib thing... why make life harder than it has to be? Let them be little.