Hi Blagdaross,
Yes … there are many people that prefer an innerspring mattress with good quality comfort layers over any other type of mattress and they can certainly be a very durable choice. In most cases the weakest link of an innerspring mattress … especially if they are made by most of the mainstream manufacturers … are in the comfort layers above the springs … not in the springs themselves. I wouldn’t exclude any type of mattress because as long as the materials and components are good quality and durable materials the choice between different types of mattresses or components is a preference choice not a “better/worse” choice.
Two sided innerspring mattresses in particular can be very durable choices even in higher weight ranges.
The people who consider them to be “outdated” are generally just “selling a story” that they want you to believe for their own reasons (usually as a justification for buying one of their non innerspring mattresses). There is more about the different types of innersprings in this article and in post #10 here.
Phoenix