In reply to Phillip Hawley.

I'm a plugin developer and I run a business based entirely around several large scale plugins that in turn are used to power thousands upon thousands of other peoples entire businesses. My entire business's revenue (and the revenue of many of my customers), which is, to be frank, not small, depends on these plugins working on top of WordPress. Over the six years that I've been operating my plugins-based business, WordPress core has not broken my plugins in a significant manner even once.

I can think of perhaps 4 examples where WordPress core made a change that I needed to account for, but that's it. Of these 4 examples, most were exceptionally minor and were quite simple to take care of before they even became a problem.

WordPress core gets blamed for things breaking far too often. The vast majority of the time when something breaks, it's due to a negligent plugin or theme developer, not WordPress core.

If WordPress core didn't care about backwards compatibility and constantly broke things, there's no way I (and many many others) could run my business on top of WordPress. I have no concerns whatsoever with the core WP developers making breaking changes that significantly impact my business.