Comment by tsimionescu

In an ideal world, 32bit would continue to be supported for as long as people use 32bit applications. If there is no good reason to port an application to 64 bit (other than the OS developers forcing it), why do it? Windows supported 16bit up until windows 10,and there were absolutely no mainstream desktop applications or even games on 16bit for over a decade at that time. That seems like a good standard.

The move to 64bit on the other hand is not all upside. There is overhead for pointer-heavy data structures, which has kept some applications from preferring it for a long time, mainly in the gaming arena. I also remember that browsers were very reticent in moving to 64 bit, until the security benefits from ASLR were overwhelming (and web apps started being so memory hungry that 2-4GB started looking small).

Also, the clear technical deficiency that you cite with ObjectiveC on 32 bits (the breaking ABI from adding private fields) is an oft defended feature in the most used native programming language in the world, C++. There, it is done because of performance optimization reasons - to avoid indirection for each structure allocated on the stack.

Overall, my point is that the technical case for 64 bit is not nearly as clear-cut as you make it out to be for many applications. I do agree that the ecosystem case for moving to 64 bit is pretty strong, but I don't think it is enough to say that developers who don't do it are idiots and dragging everyone back.

And just to be clear, I'm not being defensive or bitter, the applications I work on moved to 64 bit as soon as we could, probably 7 years ago, with very good technical reasons to do so - they were very memory hungry and benefitted greatly from having access to more than 2 GB RAM (Windows).