I've coached US and European both so I feel I can comment. For the top European athletes, indoors is not nearly so emphasized as in the NCAA. Remember, their outdoor opportunities are far superior in the summer and that's the focus. The top elite or aspiring elite European athletes are either off training in sunshine during winter or training through some remarkably harsh conditions. Some countries don't have anything close to a decent indoor track either; that 300m in Seattle would be paradise. Also, the qualifying standards/requirements for worlds indoor actually vary from country to country. The mere fact an athlete achieves a mark is often insufficient to get to the meet for his/her specific country.