Scientists make something new. One time. In a lab. Under ideal conditions. With 3 PhDs assembling, testing, and running it.

Engineers have to make the same thing so that their cheap-ass company can hire any gaggle of idiots off any street around the world and train them to assemble, test, and run 500 of the thing.

Alternatively so those same idiots can buy the product and do all manner of stupid things to it without it breaking.

Note: not saying all technicians are idiots, but the good ones get paid more so companies eventually go for the idiots instead.