So because fighting game fans are used to get shafted over the years, it's fine for the companies to continue the trend?
I love fighting games as much as the next guy, and I put a ton of quarters into my local SFII machine. But to say that they have a huge community is laughable. A few thousand people !=huge. When was the last time that you saw HD Remix or SFIV in the top 5 of Major Nelson's XBL activity list? February? March? I bet even then WAW, COD4, and Halo 3 were beating them. Those games have huge communities.
And I'll just throw this in, to rebut your list of fighting game expansions:
Tekken 5: Dark Ressurection - $20 bucks, not released on any platform that already had Tekken 5. (PS3/PSP)
Virtua Fighter 4: Evolution - $20 bucks, basically "free" update included in the greatest hits version of VF4. It didn't "go" greatest hits, the update was just included free with the GH version of VF4.
SSF2: HD remix - $15 bucks, and a HUGE update, everything redrawn, new music, new moves, and badass online play. This game still stands pound for pound as a better game than SFIV.
Guilty Gear was a horrendous series of update after update (not to mention the spin off games that tried to trick people into buying even more GG shit) all for $40 bucks, and I can see Arc doing the same damn thing with BlazBlu. But only the hardcore even CARE about Blazblu, so fine, let Arc be idiots, I'm not wasting my money on them. (And either are many others, Blazblu has failed to chart on Major Nelson's list EVER.)