I think the issue devs are having with "lite" apps is that they can't offer the full functionality for a limited time. They can't expire. Plus they require a second set of developing, updating, etc. Plus there is an issue with the user's data created in the trial period carrying over to the full app.
It's very strange that the App Store hasn't worked this out yet. Lite apps are inelegant. Between IAPs, monthly billing options, and iTunes movie rentals having expirations, I don't see why iOS can't handle free trials... All the tools are there. Maybe then we'd see more great games too.
If a developer said that they'd created an app that fully replaced Photoshop, they could easily charge $299 for it. The problem is that Photoshop users would be VERY skeptical that it could actually replace things and want to run it through its paces. Creating a lite version wouldn't help, as they'd have to restrict a ton of the features that a Photoshop user would be skeptical about. They could say it has color profiles and soft proofing, but if we can't test how accurate it is, we will be weary that they pulled it off well. It's been decades that no one has knocked Adobe off its perch, so you've really got to prove that you have the goods. When somebody does that, they could sell 50,000 copies at $300 in a short period of time and make 15 million dollars to start. The existence of that app would drive iPad Pro sales, and drive more sales of that app. The cash influx would allow the developer to improve the app more frequently. 2 years from now they could have a huge update for $99.
It doesn't sound consumer friendly, but neither are IAPs. It may just be the only way to get truly desktop quality pro apps in the store. I pay $600 a year for Adobe and their iOS apps suck. Real programs that allow you to make real money within them will cost you.
THIS!! I completely agree with everything you said!!