It also makes sense from a business point of view. The three strong points that I've taken from business school are:
1) You can overtake an incumbent if you can offer twice the value at half the price. If you can produce a drill that works two times better than existing drills at half the price, you'll overtake the drill market.
2) You can't compete with "as good as". Winning here is more marketing than anything and this is where companies like Apple and Coco-Cola shine. You can't beat Coke with point one, since it is impossible to produce something that is better than Coke. You can measure the performance differences between drills, but you can't measure the psychological value of Coke and Apple
3) You can't compete by price, unless you are dealing with a commodity product, which brings me to my point for posting.
Turning "Git hosting" into a commodity product is not a bad situation for GitLab and I honestly think this is where it's heading. In a year or two, we'll probably see less tangible/understood things become the main selling point. Such as intelligent code reviews, better code management metrics, defect predictions and so forth.
Edit:
Forgot to mention that point 3 is also where Atlassian deserves a lot of credit. They are leveraging point 3 and trying to parlay it into point 1.