Private companies should be able to manufacture electronic voting machines as long as there are anti-tampering safeguards in place and a paper trail exists. There should always be a paper receipt to put into a ballot box and a paper receipt given to the voter in case there are questionable voting practices.
I believe there is some possibility of corruption is this occurs. This is especially true in swing states such as Florida. The elections should be processed by neutral parties. The manufacturing company may be getting a kick back to help votes in certain swing states. They need to keep to the business of manufacturing and not voting.