There are several factors for this decision.
Better access for coating all the parts.
Easily replace or re coat any parts that may get damaged or scratched.
Versatility, to eventually offer different wing options
Cheaper shipping
Easy one man installation
What is it you are not a fan of? Your bumper would look no different if it were modular or welded. Strength should not be an issue but I will be testing that. All that being said, if you still are not a fan I can just as easily weld it all together.