I am not sure that is the case. If it is, I think most developers do it for money first and love second. Perhaps people on older OS don't buy apps as often as people on newer OS.
I think if there is money to be made, developers would support PalmOS still.
That's my point though. There is less and less of a reason for developers to support iOS7 with each passing day. It may be to the disdain of others but that doesn't change the facts.
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Yes, yes it is. Not everyone wants to upgrade and those customers choosing not to, should not have to suffer for it. Besides, updates are doing nothing but making older devices slower and laggy. All of more reason NOT to upgrade. Best to leave that iOS device with its original software on it.
Its funny how an iPhone 4S running iOS 5.1 seems much more responsive and fluid than an iPhone 6 huge running 8.1.2. Hmmmmm....
It's fine that people choose not to upgrade. There are however, consequences for choosing not to and losing app support is one of them. I can completely understand why someone wouldn't want to update their OS on an older device, however, I would not expect or demand that a developer still write apps for aging software.
It's all about opportunity cost. If writing apps for iOS 7 benefited the developer more than it hurt it, then they would surely be writing apps for it. However this is not the case.