It's hard to optimize for every device on the market and here in Scandinavia almost every single person young as old has a high end device so it's easy to forget to test on these older phones when everyone you know can run the game smooth as silk.
But the truth is that C2 works just fine for medium+ performance devices if you know what you're doing. It's a really great and simple engine that makes it possible for someone to create a game without any programming knowledge.
So if you want to reach the low end devices you might have to choose another engine for now. But soon the technology will be otimized and be less demanding and phones around the world will be better as well.
You can't compare C2 with buidlbox games which are super simple free casual games that the buildbox team has developed and put huge amounts in marketing to make them top the list on the app stores just to be able to use them to market their super over prized engine. The performance on buildbox is great but as said before it is really really really limited and as basic as it can be. Only good for simple casual games.
But I'm not saying that I wouldn't want a native export for C2. I would love that. But I do understand that everything costs money and if you believe that C2 should have all it's features it has atm which are alot more than most other engines and also every feature super expensive engines like buildbox has your're living in a dream world. A few hours at work and you can afford to buy a C2 licence.
But I could easily pay alot more for C2 if it one day had native export. The problem is how many would?