That was in response to your comparison with t-shirts.
And yes, scaling does not work in the same way for app development.
A large part of the required work for app development stays the same, regardless of how many actual users there are (excluding server costs (-> Sync Ultra) and probably the amount of support tickets).
But since Sync has way less users now, there has to be more income per user for it to be profitable.
I literally just explained why the price per person needs to be higher now. It is not about server costs. It is about the cost of app development and maintenance.
Of course a single user is irrelevant, but in principle and if it would evolve into a larger trend: yes.
At least if the dev wants to keep paying his bills. That is how business works. And with lower user counts at some point the required price per user would be too high to be competitive. Then the dev would have to abandon the project, since it would not be profitable anymore. He is a full-time developer after all.