Hi Anut,
Curious. Whenever I try a melt test in the microwave the cheese just bubbles and goes stretchy, but doesn't flow. But the Lancashire and Butterkase I'm eating now both melt fine on potatoes, just not in the microwave. I think I had one cheese, a Dunlop, that melted like your example in the microwave, but it's not been common.
And to be fair, I've only made caerphilly 5 times. I'm sure there are others who have made it more than I have. I just think it's an ideal cheese for those just getting into making pressed cheeses. It's tasty, and you can get to eating it relatively quickly. I also think it's a very good cheese in it's own right, so it's nice to have some around!
- Jeff