@Sébastien, you comments are very pertinent. I agree with you mostly.
I think people who have used BI tools will have a easier and clearer understanding of the benefits of modern OLAP (or so called real OLAP), so i don't worry about the acceptance for the modern OLAP.
As you mentioned our product, esProc, i believe, esProc is a perfect solution for the drawbacks of OLAP above. Off course, it can't replace R or MDX, but, just as you say, DAX makes modeling easier, but esProc supports same analytics without modeling beforehand.
It may take ordinary businessman a little time to learn, but for business analysts who have not much technical background and IT developers engaged for a bigger project, esProc is ideal script with features such as, intuitive syntax, easy to learn, powerful computation capability, and most importantly, strong functionality to meet all requirements.