I've had master cylinders bad when brand new. And, some bad rebuilds. Normally, it was a problem with the metal being damaged or porous. Only name brand that I've consistently had problems with is Fisher. I simply avoid them.

As for getting several bad in a row, doubt it. Most likely, it was the very common problem of air entrapment in your system. Very few people bleed up high. That's a shame as it's very effective and easy. Far more effective and easier then trying to start out working down at the wheel cylinders.