Welcome to the Internet Economy, where middlemen are cut out if they don't add value to the deal.
Distributors were used because manufacturers didn't want to sell in small quantities, and wanted to keep control of prices. Disty's would buy in quantity, keep items in stock, and resell in smaller quantities for a profit. Everyone benefited, customers got local access to parts and manufacturers shifted the cost of sales to the disty.
Now, most distributors don't stock much and order from the manufacturer as needed. Why should I buy from a middleman when I can buy direct? why should the company sell to a middleman when it's now cheap to sell direct or through Amazon?
You've only got 3 things to sell , Price - Delivery - Quality. I was taught in salesman school that you needed to do at least 2 of those as good or better than the competition to make the sale.