I care for the simple reason that I want to know what I'm smoking. I wouldn't care if they were blended if I was told that fact, then I could choose to smoke it or not.
Take beer since you are pretty knowledgeable about beer... would you say that you wouldn't care at all about what ingredients are in the beer or where the hops come from etc and would be happy just saying you like it or not? Sure there's always times where you could care less and just want a good beer, but for the most part, you like beer enough that you actually care what's in it and possibly where the ingredients are from. You don't want to drink a beer where the producer is lying to you and not sharing ingredients/info about it.
Same as cigars, I simply want to know. Not that I'm being a snob cuz I want to know about any cigar I'm smoking... Nicaraguan, Dominican etc. I just don't want any BS.
And for the record, I have no clue if Cuba is producing cigars with other country's tobacco. I do think it's very interesting that Cuba officially allowed the Robaina's to start growing in Ecuador... why would they do that? Maybe to start having other tobacco ready if/when the embargo is lifted, or to ship some to Cuba to produce now... who knows.