No. of Recommendations: 3
Now, don't take this as an affront; I like the cut of your jib, but...
This argument - interoperability - is rather silly. One has been able to attach files to emails, texts, dropbox, etc for decades. There's no need for Apple to be forced to avail this technology to others. One need not have an Apple device to send/receive to other Apple devices. I think I first sent and received to an Apple device in 1983. From other devices. They're interoperable just fine. This was my profession for decades.
Same-same, file formats. A .xls can be read in Google docs, and used between Macs and PCs with relatively no friction, and that's been true for a generation also.