Apple devices obsolete after 18 months?

The original IPad was the current model until superceded by the iPad 2 in March 2011. 18 months later Apple are no longer providing IOS updates for the iPad 1 and app updates are appearing which require a minimum of IOS 6 and cannot therefore be installed.

I appreciate devices can’t be supported for ever but making devices obsolete after 18 months is totally unacceptable.

Will you buy an Apple device now that you know it may not be fully functional in 18 months time?