Today at Ezeiza, ATC seemed determined to only use runway 35 for takeoffs and landings, despite 11/29 being open, and the wind easily within limits to use it in either direction (more or less 010/15 all day and CAVOK). As 35 requires a backtrack for takeoff, this caused long waits for departures, and we even had to hold for twenty minutes upon arrival, despite light winds and visibility unrestricted. Is this some kind of protest?.