I still have boxes with nearly every tape I ever had going back to 1975. Pretty surprising to find out after storing them in hot and freezing attics and summers in hot cars even cheapo ones still work. I assumed by now they would all be disintegrated or would immediately self-destruct upon attempting to play.
I still have a Kenwood KX-1030 3-head cassette deck in perfect shape. It’s all packed up for shipping but I can’t even find anyone interested in taking it off my hands now. It was an awesome deck in its day.
In a way, he probably feels like the MP3 player was the next logical step in what he was working towards: portable, convenient music. I would suppose that he would regret it not being a Philips innovation, but hey, the cassette took off under Sony and other manufacturers.