Low Signal from Single Transistor Pierce Oscillator Mysteriously Turns High
You probably had a bad connection the first time around -- either you explicitly plugged something in wrong, or you had some corrosion on a wire or something.  I've been there, done that.

Generally your last goal with an oscillator is to get a clean, high-amplitude sine wave.  You can make that from the waveshape you have.  What you usually are interested in is good frequency stability and phase noise characteristics (or jitter, if that's how you want to specify things).  While there are crystal oscillators that'll get you a nice clean sine wave, I don't think you'll get it from this circuit.