So very much this. I see it often even as early as level 1, the other 4 players on my team all hiding in a bush and *sometimes* they score a level 1 gank. I can only imagine they're all doing internet high fives while I watch the enemy teams exp start pulling away by level 1 from them getting exp in all 3 lanes.
That and the bloody mines map where people don't understand that the first mine opening has more skulls from little packs and less from the boss. Then with each following mine opening it shifts the other way, more skulls going to the boss and less from the smaller packs. See it all the time they run straight to boss on first mines all together (usually complaining about me not helping) while I desperately try to prevent the enemy team from getting every merc camp on the map. (While just one person on their team runs around collecting skulls from the small packs and gets nearly as many as my team starting on golem)
I try to explain it but generally nobody bothers to reply, spread the knowledge so this can stop :P