'My curve' is 'ugly' because I just mixed two curves together into one single graph to demonstrate my idea. I mean, if one used one single curve (maybe a sigmoid one?) instead, which also starts flat and ends not so steep, then it would have the same effect, but just looked much better. :)
You are right, in general there is no problem with looking 'ugly' of course.
Your example curve looks more or less linear ... :)

