"R&D" is what SWEs do. If you're developing anything new, such as a new software system, then you are doing R&D by definition.

"Production" is something like building the same factory that was built thousands of times before, to fabricate the same widgets that were fully designed by an R&D team.

The actual top researchers at a place like Google would be making way more than $250k.

I cast a super wide net to show how ridiculous the original statement was.