That was a just plot twist (play against another DK), not a badly designed puzzle. They are very different.

The author is complaining that because the game didn't warn him to change his strategy, he was unfairly beaten and forced to restart the level (and so wasting his valuable time and money). And indeed, you cannot break enemy walls in DK1, nor can they break yours, that's by design.

But this is just playing a 30 year old game with today's mindset. Now everything is faster, gamers have more limited time and even more limited attention spans and different expectations. Back then, you would just see it as a challenge, restart and beat the level, all without making any fuss about it.

It's like, did people in the middle ages complain that washing was hard and they needed washing machines to save time?

Probably not, but people today certainly would. It comes down to expectations.

Which sounds like weird complain as whole history of videogames was essentially build on failing and trying again. Learning and adapting to changes, part of which is failure doesn't really seem anyway unreasonable to me.