1. We are the first, or we are the first to get close to the singularity in our light cone.
or
2. Generating energies or over coming the challenges of even traveling close to the speed of light is hard.
or
3. Space is big. You just won’t believe how vastly, hugely, mind-bogglingly big it is. I mean, you may think it’s a long way down the road to the drug store, but that’s just peanuts to space.
or
4. They have.
Think a bit about this one. Let's define singularity as the ability to either a. upgrade our brains without any biological limits or b. upload our consciousness to a computer that can be upgraded without limits, as immortality and all other consequences will follow from this. Interfering with a pre-singularity race would be the equivalent of us using a newly discovered limitless brain enhancing technology to bring monkeys, dolphins and even cockroaches, as from our infinitely high level downwards a monkey would seen close in intelligence to a cockroach, to human and then limitless superhuman levels! Think about this for a moment! Would you want to waste your technology to "upgrade" inferior life (and possibly trespassing their "free will to choose their own evolutionary strategy"), when you could create new intelligence from scratch that would be designed to evolve faster and be more like you so you could feel empathy for it?
I don't think a post-singularity civilization would bother contacting a pre-singularity one. They would either analyze it stealthly without interfering ...or just use them or their homeworld for resources without caring about their fate or even their survival!
Now, assuming there really is a discernible point of "singularity" by the a. and b. mentioned above, the meeting of two post-singularity civilizations would be a whole different thing. I think we have quite a bit to "grow up" until we get invited into any "galactic club" :)
2. It doesn't matter; the galaxy can be completely converted to computronium in around 10M years even at 1% of the speed of light.
3. Exponential growth is bigger than space.
4. ...or in a simulation.
Some people think that space is expanding as well. These people think that intra-galactic distances are relatively consistent, but inter-galactic distances are increasing in an accelerating fashion.
"Additionally, the expansion rate of the universe has been measured to be accelerating due to the repulsive force of dark energy which appears in the theoretical models as a cosmological constant. This acceleration of the universe, or "cosmic jerk", has only recently become measurable, and billions of years ago, the universe's expansion rate was actually decelerating due to the gravitational attraction of the matter content of the universe. According to the simplest extrapolation of the currently-favored cosmological model (known as "ΛCDM"), however, the dark energy acceleration will dominate on into the future."