I was spoting at DEN Sat. afternoon, the winds were 340 @ 34 kts gusting 39 kts. Visibility was 1 and 1/2. All departing aircraft was using RWY 34 and landing 35 R. There were at least 10 aircraft waiting to take the active. My question is why was that the only RWY open for departures? I know the wind was straight down the RWY but why not 35L too? Is the crosswind component too much to handle.