I don't think the two of you are necessarily disagreeing, just focussing on different aspects which I agree with.

Isner and Karkovic boring games to watch, personally I agree, more particularly when they play similarish players. I do see some interest in an Andy or Novak taking their 'game' on and generally dismantling it. It can on days when they are serving particularly well, like Isner yesterday, be quite a mental challenge.

But for their frames I absolutely agree with Oakland what great athletes. Also realising from early on the possibilities with a great serve allied to their height they have made their serves huge weapons. Eminently sensible to extract maximum possible advantage from that and overall, considering everything, they have done so well in tennis. Different ways to skin a cat and it's not their job to make it enjoyable to all, even more especially when height does restrict certain abilities.

Of course they are skilled in other areas, just probably not top 100 skilled or whatever. They couldn't get where they are on their serves and occasional volleys alone.