FUD Zilla claims TSMC mainly went ahead with its 20nm process to get deals with Qualcomm and Apple. Other firms like AMD and NVIDIA are rumored to skip the process to go straight to TSMC's 16nm FinFET (16FF) node, which will be updated to 16FF+ in just a few quarters.
While some segments have the luxury of skipping this node, others do not. Nvidia and AMD can afford to ditch 20nm for their GPUs, but companies like Qualcomm, Apple and Samsung cannot.
With that in mind, TSMC knew that it would be worthwhile - Qualcomm needed a new node and so did Apple (for different reasons). Samsung also has a 20nm node and Apple uses both for A8 SoC production. Samsung also uses its node for the latest Exynos series application processors, but Qualcomm would have been in trouble had it not been for TSMC's node.
As far as the rest of the industry goes, we did not hear a lot of kind words about the 20nm node - with descriptions ranging from "pointless" to "broken" or any of a number of dirty words. However, TSMC needed it for Qualcomm - without it, the node made next to no sense at all.