The quotes seem unnecessary. Programming isn't just an expert activity. Many applications offer macro recording and other facilities to create programs without scripting. Dataflow programming is often used in graphics and media applications. Spreadsheets are one very successful implementation of dataflow programming.
What Excel doesn't let you do (without heroic effort in support toolchains) is software engineering...
It also allows domain experts to program. So while they may not be expert programmers, they are experts in the problem area and will come up with expert solutions.
What Excel doesn't let you do (without heroic effort in support toolchains) is software engineering...