If you live in U.S then I can honestly tell you that you are correct and several people have noticed this as well. Queue in the daytime yields a lot of foreign players as well as generally worse range and queue times for searches. Queuing from about 8:00 am cst-1:00 pm will almost certainly get you a horrible group of team mates. If you want more quality games try to play in evening hours. The later the better, especially after 8:00 pm or so.