A tightly focused beam of light would have to hit us randomly and unintentionally, since we must assume that no one knows that Earth exists or where it is in the universe. Even if the beam were the size of Earth's orbit around the sun, someone would still have to target our one particular sun at random among the billions out there. If you fired off at one star in our galaxy every second it would take about 32000 years to hit them all. (Please correct my math if I'm wrong) Sure, someone could have advanced far enough to have sent these to Earth in the past, but where were we to receive it? It doesn't seem like a very fruitful idea to me, but I'm not a professional scientist.
I think it IS good that SETI is trying new things, stoking interest, and providing reasons to continue being funded. It's an important undertaking and one that we should continue on strongly. We should be patient, too. As patient as a species that only lives for a cosmological nanosecond can be...

Yes, first of all, the odds of lazed light hitting us and being detected is minute. But I wanted to make the point that lazed light does not necessarily remain lazed over those distances and going through interstellar dust.