To give you some perspective, a startup I worked for began with a self-hosted web analytics option.
In fact, most of the systems we had were all homegrown and while initially it was a great idea - the maintenance part of it took a lot of time away from optimizing on generating revenue.
We spent a lot of time trying to figure out the structure of our self-hosted web analytics platform, how it tracks data, how it stores data, etc. The majority of our company were engineers but we still wasted a lot of time fiddling with the self-hosted analytics.
There will likely be a subset of customers who would be interested in self-hosted but I'm willing to bet that they are more likely to be companies more engineering-oriented.