A few points:

Retailers are not making anything like 40% on bikes. That would be a dream come true.

Secondly, there are jobs other than Manufactoring. My guess is that most people on this forum don't work in manufacturing.

Buying a bike from a domestically owned company means you are supporting jobs in that country that include, but are not limited to:

The engineers who design the bike
The marketers
The people who work in the offices of that company
Those who work for the distributors
Those who work for shipping companies
Those who handle the financial end of the business
Those who assemble or those who provide the tools for you to assemble the bike

And all the people who work for all the companies that support those workers

And on and on

There's nohing wrong with what the OP is trying to do and I certainly don't see why anyone would see it as naive.