I think it's getting harder, now the world is getting more developers and more fully funded startups.
Why do you think it's getting harder? I think it's always been hard and will continue to be hard. There are a few opportunities and it takes lots of time to exploit them if you get to them at the right time.
Simply because all the niche's for software are getting filled. Leaving only opportunities with huge hurdles to get over, which is hard for one man companies.
In the early days micro isv's were fairly common, and well known. I don't hear much about them anymore.