Then the solution is not for Shimano to enforce MAP overseas, but to instead stop enforcing it in the States. "MAP loopholes" haven't killed your business, MAP has.
Amazon will just sell everything just above the cost of the good and all the small stores will go bankrupt. We seen this with CPG and groceries with Walmart moving into a city.
For huge retailers as amazon it should be illegal to sell things for less than the average price of the cheapest -lets say- 20 stores where that product is sold in the country (with huge penalties for trying to artificially reduce the average price like creating fake stores or bribing store managers)
Thats what MAP was suppose to do. The brands don't want all their sales from one distribution partner because that distribution partner will have enormous leverage.
Where MAP fails is if brands want to different prices globally. This is because items will just get re-imported if they are priced lower in other countries. They want the benefits of globalization which is cheaper labor and materials but don't want to negative aspects which is the same price globally for the product.
The playing field is still unlevel - those overseas retailers don't pay sales tax and are still getting the products cheaper than they are made available to US retailers. The US government even subsidizes some overseas shipping, making it more affordable for overseas retailers to reach a US audience!
MAP agreements are illegal in EU. They were specifically banned, and for good reason. Which is why calling Shimano's stance a "refusal" to deal with some problem gets you a negative response.
Still, feel you on the retail apocalypse, and how every other new internet darling can somehow skirt taxes or... and the problem is unfixable until right after it doesn't matter anymore. It took something like twenty years for Amazon to start paying US sales taxes most of the time, in many cities Uber's business model was price dumping etc.
Apple and Garmin manage to successfully enforce MAP. Nintendo, Sega, and Sony before them. Parallel Import Law is the means they use to do so.
Shimano could, were they willing, use Parallel Import laws to prevent European retailers from selling those products in the American market. They've chosen not to. So whether one likes hearing it called a "refusal" or not, I think that's what it is.