Production bikes built now all have robotically laced wheels. They never stay true. Never properly tensioned, and the spokes will loosen up as they seat in and you've got a wobbly wheel. Most human-built wheels will stay true for a long time, no matter the spoke guage, as long as they're built right. I've built wheels for klunkers that get beat to hell on trails, motorized bikes that get raced on go kart tracks at speeds of 45-50mph, bar-hopping beach cruisers that get seriously mistreated, and the only time they get tweaked is from hitting curbs, rocks, and other immovable objects. Even with alloy wheels and 15g spokes. Junky rear hubs, and hubs that aren't maintained are a big problem, especially with those that are, uh, on the huskier side. Riding style is a major factor, too. If you're a big guy and never get off the seat, you're crushing the bike over potholes, curbs, etc. Gotta learn to unweight yourself and glide.