Seems like back in the Day, everyone wanted AD&D.
Nobody told Marc to design Traveller, at least not as far as I am aware.
Following the market means catering overblown comic book art splat books of feats and prestige classes to the world of the Console gamer via open license D&D 3.5, who all feel that intellectual property is for other people to pay for, that want to "try before they buy" via BitTorrent.
Regardless of the fractured and aging Traveller fan base, etc, and everything else you imply all over the place here, T5 won't make him money because Roleplaying games as a whole are being crushed by .pdf scan filesharing services like Kazaa, and moving from book to non-scannable miniatures games like Clicks, and Warhammer.
I personally don't think he's in it for the money, any more. I think it's more of a "This is what I've done with my life." And he wants to finish it, his way, his vision. That's my guess.
Clamoring for him to make his vision marketable...What are you worried about? You already hate it, before it's been released...What do you care, seriously, if it fails?
What will you, personally, lose?
It won't make money anyway. Correct me if I am wrong, but the Majority of people that like Traveller prefer Classic, and they found it somewhere between age 10 and 20 about 25 years ago, plus or minus.
Game systems have evolved since then, and sure, It might be Absolutely Grand if Marc produces something to rival TSR's Alternity, on his own, or with some assistance, but the Magic Genie can only be captured a few times, and perhaps Classic Traveller was it.
The fact that Marc is still around, says something about his spirit. For real.
If I had designed CT, and had to go through all the ups, and downs of all the different editions, market changes, trying to save Traveller...
CCG's killing hobby stores, and all along the people running WOTC making lists of Wargames Companies they are gonna Drive Out of Business This Year, and laughing about it... (because, let's recall GDW was a War Game business, when it started)
I personally would have quit, long ago.
I won't lie, I admire what MWM has done. As a gamer, as a person. As we speak, he's helping new companies get launched. I've talked to people that he's helping, and they greatly appreciate his efforts to mentor them.
For sure, Gygax has his own problems, he got kicked to the curb, he got a raw deal in the Dangerous Journeys thing, and he's somehow still hanging on, but it's not like it was in 1979.
I'm frankly still surprised that Steve Jackson is still around. Ditto for HERO Games.
R. Talsorian, I always thought they'd survive,since they grabbed a niche and held on tight.
West End Games is now mainly WOTC, or scattered to the winds.
Last Unicorn, Gone. A SHAME. What might have the DUNE RPG Wrought in sci-fi Gaming?
FASA, gone. Or, okay, it's WhizKids, I guess. But they aren't the same. Not by a mile.
Yaquinto, gone.
Leading Edge, Gone.
FGU, Gone.
ICE, gone, but back, just a few year to late to have missed the LOTR movies.
Times are changing. Traveller, being vested in pretty much one guy...it's up to him to change CT to T5, if he wants it to. Or not.
I'm not holding my breath on seeing Grand Survey 2.0, either, but I keep hoping.
Some things never change, and some people, also.
*shrug*