I get both sides of the debate. I never had an issue either skipping the BAF and buying the ones I wanted, or viewing the couple I didn't want to complete the BAF I did as the price I was paying for that extra figure. But, like SD noted, that was when prices were lower all the way around (not just for the figures, but everything else in our lives). With figures now approaching $30, and things like rent/mortgage and groceries being sky high, it's not so easy to justify the purchases anymore just to complete a BAF. I want Skurge, but I can't justify paying almost $180 to get him.
The fact of the matter is, we're now in a place of massive economic uncertainty for many of us. I know I'm now financially the most insecure I've been since my early twenties when I was a poor college student. There are SO many figures I would have bought without question in recent years that I now find myself either passing on or waiting for sales. There was a time I would have happily bought every single one of these figures in this wave, and would have probably only gotten rid of that ugly Iron Man. Now, I'm looking at it thinking "well, I REALLY want Werewolf By Night and Phantom Rider. I like Warbow, but I guess Crystar is going to be solo on the shelf. I don't need a six-armed Spidey in the black costume, and I guess the older Enchantress figure will have to remain in the display for now". First world problems, and all that, but it still puts a damper on the overall joy of the hobby.
Yes, it is true that the BAF wave gives us characters we'd otherwise never get, and that is still the strongest point in its favor. In that regard, I'm happy it exists. In the past this would have just been viewed as a win-win by me, but...once again...the stupid economy. THAT is the biggest issue for the BAF at this point, and it's likely to be the factor that does it in.
Oh, and fuck Trump!