I had a bb axle snap on one bike - I've had it with hammering on the crank, no matter how well it's supported. Maybe back in the day the cotterpins popped out for any well trained, fully equiped mechanic, but after sitting around for 40 years 50% of the cotterpins on the filthy dirty, neglected bikes I come across are pretty pissed and they don't like being hammered on. I've had a bike shop mushroom a cotterpin with a 50 pound, three foot long cotter press.

Nothing is easier than drilling it out. Start with a 1/8th inch bit, and work up from there. Takes a second, the metal is so soft. By the time I got to the bike store, asked them to use their giant cotter press, paid my bill, and drove back - I can remove them myself, kiss the kids, trim my nails, and have a gin and tonic.

Now, if it's the cotter pin I installed when I rebuilt the bottom bracket last year, then yes, a tap at the right angle, with the right strength pops it right out.