Using a Falcon 9 at 25 satellites per launch it would take 177 flights, about 36 flights per year.
Using a Falcon Heavy with 40 satellites it would take 112 flights, over 5 years that's about 22 flights per year.
Using a BFR assuming 350 satellites per launch, until someone comes up with a better number, would need 13 flights total.
now those are based on the old higher orbit so presumably the numbers move substantially with this new plan.
Not only that, but the companies first successful orbital launch was only 10 years ago!
In those 10 years they went from being literally laughed out of rooms, to being the forefront of the industry. And even now that they are arguably "on top" in many ways, they keep on trying to do these insane things.
They are currently trying to build a rocket with the largest launch capacity in history, launch and maintain a satellite network which is the largest in history (if successful, it won't just be the largest, but will be at or near half of all satellites in orbit!), and still have a goal of getting humans to mars.
Say what you will about Elon Musk, the guy knows how to set goals.
[1]https://www.reddit.com/r/Starlink/comments/7zqm2c/starlink_f...