Maybe its because there are so many successful tech blogs to look up to (like labnol), almost every other blogger is a tech blogger today. Another reason might be that a tech related blog is an easy way to reach out a global audience.
The more important question for newbie bloggers who are trying to select the most appropriate niche for their blog is, has the tech niche become redundant as there are already so many tech blogs out there? And most of them are actually just rehashing the content of some other big tec blog and posting it on their blog. What's your opinoin about the tech niche in blogging in terms of profitability and relevancy ?