Sorry, but it's not the Chinese. They build whatever their customer holds them to.
Realize that this saw was built to be the most economical it could be for a segment of the market that wants many of the conveniences of a wetsaw without the full pricetag. For example, I've owned a number of MK770 saws. They are what most pros would consider to be a professional quality 7" saw. It is build much more stout than all the plastic parts I'm seeing in the pictures. It's not the top of the line saw in this category with a heavy motor or anything. But costs about 3 times more than what you paid.
Since you've modified it and can't take it back, I'd consider reaching out to a factory rep that may be able to assist you with the alignment problem.