Seeds or bulbs?

The onions on the left were started from bulbs from the store and the onions on the right were started from seed. Granted they are two different varieties, but the bulb starts went right to seed with no bulbing at at all. 

The onions that we started  by seed, are cruising along doing just fine. This is the second time we've had this happen....and from now on, all of our onions will be planted from seed!