WebSummit was full of them. Apparently, there are 5 PR people for every journalist on earth. Each journalists in the tech world receives about 200 emails, pitches, stories per day. I listened to a panel with PR people and journalists discussing thing with each other. Here are my impressions partly driven by what they said, partly what I read between the lines.
Your product is actually not that interesting to them. Two hundred products per day, lots of copy cats ("Uber for X"). I actually think journalists don't have time, take the time to understand a technology, and hence don't find it interesting and/or write about it. It takes me a good 45 minutes to understand a company well, a journalist does not have that time, the reader does not have that time, and most journalists don't have an engineering background.
Big milestones are actually not that interesting anymore. Everyone raises $100m at a $1b valuation.
Other aspects of "your story" (becomes a buzzword) are more interesting. Did you come from an unusual background, does your company have some sort of social, environmental purpose (primary, or a side effect).
Do you actually need to be in a major Silicon Valley tech publication? If your target customers are in those circles, then yes. Maybe if you need to those "featured in" logos on your web page to strengthen your pitch to SV investors, yes. But otherwise, maybe spend your time and effort somewhere else.
"Social media" is becoming crowded and busy as well. With so many people creating noise, it actually boils down to a product that people want to use and talk about to their friends. Not so much social media, more building a great product.
So all of this is not to blame on journalists and PR people, it is just very crowded and noisy out there.