Reading through the many posts I can understand the frustration that games may not be running smoothly when exported to mobile devices, I'm in the process of developing myself, but not at that stage yet.
Due to the way Construct works and provides users with a very simple way of game creation, I think a number of users abuse this and fail to optimise their product & a lot of the fault is their own. You can't really expect to create something & throw together numerous Hi Def sprites, god knows how many particle systems and physics going on, without testing, testing, testing and expect to work as you think it is supposed to in your mind.
I think a lot of users take for granted that they do not have to use/learn code in Construct 2, a coder will optimise, refine & sacrifice elements of a game to get the performance results they need on other platforms, where by it would appear by the numerous posts Construct 2 users seem to think they can get away without any of this?
There are always alternatives out there, so you could always learn to code and use an alternative engine, I’m no coder myself & unless I want to put the 10,000 hours in to become proficient, then Construct 2 allows me to experiment & potentially release my ideas.