The SE is not weaker than the 6s, it's only limitations were the older case that would not easily allow force touch. Other than that , it's as good as the flagship. They won't have the case limitations on a brand new model. And I think Apple has learned it's lesson from the 5C, and now the demand for the SE. Apple customers want a great product. And people are willing to pay for an older iPhone to get that great Apple product even if it's a year or two old as their entry level phone.
People always expect to get the best from Apple, and if a budget low spec phone is what a customer wants, then there are lots of Android phones for a customer to choose from. Getting into that space is not a winning strategy for anyone much less Apple.
The selfie camera isn't as good in the SE as in the 6s. But you are right that the rear camera, which is much more important, is the same as the 6s. So I guess with the same chip and the same rear camera, the SE is pretty much a 6s. Hmm, maybe you will be right after all. That would be great. Thinking about the SE price point, and I'm thinking again that the 7 will launch at a cheaper price than the 6S.