Fran-
I think all synthe manufacturers have been guilty of this throughout the 90's. Yes Korg have rehashed their products but so have Roland in the same way. Your opinion regarding Korg and Roland is taken but I own a fair bit of gear from both companies and can honestly say that each has it's own sound.

If I was trapped on a desert Island I would take a Korg Triton (fully loaded) with a Roland JV2080 (fully loaded) as my only 2 sound sources.

Of course I would need heaps of storage media, a couple of decent mics and monitoring etc- but this could be a whole seperate topic. Cheers.