Yes, I certainly agree. One of the major problems with taking an application implemented on a PaaS solution to production scale is that you essentially join at the hip the continued success of your core product to the eventual fate of an outside vendor's platform. What's worse is that by the time you realise you've grown too big for the PaaS you may have to expend a huge amount of engineering effort and customer good will to move off, if you even can. Indeed, PaaS providers will try to make it /easy/ for you to make engineering decisions which lock you into their platforms -- and they will present those choices as helpful at the time, which makes them quite insidious partners.