Below 10,000 ft, airplanes are travelling at less than 250 mph. At takeoff, it's closer to 175 mph for a jet like a 737. At less than a perpendicular angle, the rate of travel across a field of view is less than that. If a person holds their arm out they can point with a lot of precision -- it's a lot easier than tracking an object at the same distance with binoculars. Furthermore, you must consider being at a distance away from the airplane. The greater the distance, the slower the plane is moving and the easier it is to aim at. Pointing straight up is rarely the issue, but if you're a mile away and the plane is on approach at say 2000 ft, that's only a 20 degree angle. Sitting in the cockpit of a 737, a pilot can see the edge of a taxiway -- the vertical field of view out the window is quite good. The lasers involved in these incidents are often much more powerful than a pen laser pointer and are many are strong enough to cause permanent eye damage. Unlike an incandescent bulb, lasers lose very little energy on the way to their targets. It's like those idiots on the highway who blind you with high beams at night, only much worse -- and I've had my night vision temporarily ruined by headlights a couple miles away. Lastly, there are lots of metal bits in a cockpit to reflect the laser, and the windshields are often marked by micro-abrasions from dust and insects, which can cause the whole windshield to glow.
Here is what it looks like from the cockpit. Are pilots bullshitting? Try driving a car down an unlit rural road at night with that in your eyes and report back to us.
A 1 watt laser is enough to flash the ISS. It doesn't take much.