Can some hifi components lessen (or negate) the impact of brick-walling/compression?

I find such mastering only becomes less tolerable on better equipment. I am sorry to say.

A number of poorly mastered discs with no dynamic range, that otherwise had inspired performances, were okay on my walkman or old Onkyo micro system. Stick them through a serious system and they are 100% unlistenable.

While I wholeheartedly agree that a really good system can get the best from a bad recording and still make it more enjoyable, recordings can be bad for different reasons. Dynamic Range compression is, to me, the one sin that cannot be rescued and how offputting it is is directly proportional to the quality of the hifi played on.

So I cannot explain your findings. I assume your friend has proper gear. Your experience goes against everything I've ever heard regarding DR compression. I don't see how you can reliably expand the dynamic range with any degree of faithfulness.

My wife has noted that my system seems to descriminate and make every album she buys (generally she buys J-pop) so unbearable that even one full album play is impossible. On the hand, the unforgiving nature of hifi with DR compression combined with my utter hate of J-pop works in my favor here. 

I also subscribe to two seemingly opposing views, in that a better hifi generally improves the musical experience on all recordings and also makes some albums quite tiresome listen to, and so to my ears, unlistenable. The unlistenable aspect is generally down to the flaws/crimes of the recording & mastering becoming just too intrusive. Dynamic range limiting/brickwalling is particularly tiresome. Massive frequency imbalances also drive me nuts, especially when the bass has been eq'd down to zero. 

Simplistic musical arrangements, (I feel your pain Mr Zen, I have been assailed by K-pop for the last decade), also can disappoint on playback through a good system.  There's just so little happening, and so little art involved. You get bored and move on, or contemplate self harm.

The opposite of this is that demanding music, which might be so mangled by the ghetto blaster that you can't bear it, is presented well by the great hifi. Provided they haven't murdered it in the studio, so that you can involve yourself in the musical experience. 

I have so many great albums that if a piece is well played, but the recording is poor, I just move on to something that doesn't grate. Yes it might be a great performance, and the artist is really interesting, but I've got heaps of music with both of these  aspects so why put up with crap sound? Two out of three doesn't cut it.

I liken this to food: I love a great steak, but if you burn my waygu to charcoal I'll leave it on the plate. Additionally, if you're starving, then soggy chips with lots of salt go down well. But if you're able to choose, lobster and champagne cooked by a great chef is the way to go. Good hifi let's you "dine out" in style every night.

I agree with Steve. I also think that some of us tolerate defects in recordings and equipment better than others. Perhaps picking up very small nuances that others may miss. Maybe that's why some hear differences in cable more readily. Just because you or I can't hear a difference doesn't mean other people can't. Rich 

it is crazy, they are in practice amplitude-modulating the signal by using very fast attack on compressors and limiters  (often muti-band-comressors that splits the signal into small frequency bands treated separately, i.e. in practice modulating the overtone structure).

the EBU has setup a metering standard (EBU R 128) for radio stations but I dont know if many use it . i like the idea. rather than metering the electrical level they try to go for perceived loudness and this punishes the brickwall-mixes.

a very good lecture on loudness, hearing, perception is on yuotube, search for ”EBU R128 Introduction” (by Florian Camerer).