As a frustrated Star Trek Minimates collector, I feel your pain. DST seems to have a huge hard-on for TOS and it's lasted much longer than four hours.
They launched 3-inch Minimates with six SKUs of TOS in 2002. It never saw a second assortment.
They redid Trek Minimates with the 2-inch bodies in 2007, expanding the TOS selection to 18 SKUs while only offering two from DS9 and one from TNG. That lasted five series.
Then they rebooted Trek Minimates yet again in 2013 with two Legacy assortments that had a better SKU balance (2 TNG, 2 DS9, 2 TOS, and one each from ENT and VOY) but the Minimates starship line was exclusively TOS (4 SKUs of Enterprise variants). Legacy never made it to a second assortment.
This year they offered an assortment of the TOS bridge crew to retailers. There wasn't enough interest so DST apparently gave up as if they were out of source material.
Of course there's plenty of untapped source material from TOS, both film and television, but DST went the easy route, the safe route, and essentially offered the exact same product they had before in presumably different packaging. Collectors who'd already acquired that crew weren't interested and newbies didn't even know about it because it never even got solicited.
I can't help thinking that anything BUT TOS at this point would garner more interest. I'd wager even the same character assortment offered in uniforms from ANY of the six films would have fared better. But there seems to be an unwillingness on the part of DST to take a chance on anything but the original TV show. They might nervously dabble in other eras but they've never gone balls deep with TNG, VOY, et al as they have repeatedly with TOS.
That said, Star Trek is not Stargate or BSG. The latter two aspire to have the kind of brand awareness that Star Trek has enjoyed over the last 50 years. My expectations would be much higher for Trek merchandise than those two, and I entertain no illusions that Star Trek is anywhere near the peak popularity it enjoyed when TNG and DS9 were new and TOS was alive and well on the silver screen.
A generational shift is here. Original fans of TOS are literally dying off. The Trek their kids enjoyed most took place in the 24th century, not the 23rd. Those kids are now adults brimming with the same nostalgia that kept TOS going for so long. It's time to offer them the tchotchke they'd like, whether it's a block figure version of the crew of the 1701-E or a desk-worthy electronic replica of Deep Space Nine.
In short, yes, DST's Trek line needs to boldly go where it hasn't, or at least in a way DST's not 100% comfortable with if they're going to keep this license moving forward.