I guess that "good" here means things like not blowing up often and putting the payload in a very exact orbit, or reliability of the launch itself.
For example, Ariane 5 (not counting the first few failures when it still had teething problems) is extremely reliable - it was supposed to launch people, after all, which means extra reliability constraints. It can also put its payload in orbit with an incredible precision. And it easily churn out half a dozen rockets a year (it often launch 2 satellites at once - again, massive payload because it was supposed to launch people).
But compared to, say, a smaller, simpler Proton, it is sooo expensive. There is a reason why you'll find Soyuz and Vega too at in Arianespace's catalogue.
On the other hand, said Proton, while being able to launch fairly often as well, tends to messily crash or otherwise fail about once or twice a year.
For the moment, SpaceX is on the third point of the triangle, cheap, good (AFAICT - at least they have yet to blow satellites up), but they have a hard time launching 3 rockets a year.
Maybe launching rockets regularly will mean driving prices up. Or maybe it will mean not being quite as safe and precise. Or maybe they will continue this way and provide a good and cheap service - if you are not in a hurry. Or maybe they will manage to balance all three.
Either will be a good thing - they are already forcing other players to adapt, and that won't change.
The funny part is that SpaceX rockets, like all rockets, are based on decades-old technology. It's been refined over time, but you'll note that Soyuz, one of the top rockets and the only way for the three biggest space players to send people as of today, is 50 years old.