Bottom line, for me, is that as long as FDev make it possible to earn enough to pay the rent upkeep on my FC by doing enjoyable things, I'll be happy.
The OP raises a valid point, though, even if it's not necessarily for the right reasons.
Being able to earn Cr50m/hr (other esimates are available) might not help small-pad ship progression, and it might make it slightly more long-winded to buy & outfit a Corvette but, erm, so what?
If FDev have decided that's the way things should be in the ED universe, so be it.
I guess anybody who's lucky enough to have been around for the era of Old Nu-Mining was just that; lucky.
Honestly, I think any issues related to the use of small ships should be considered separately to that of economics (if that's even FDev's motivation here, at all).
Like I've said once or twice (or a hundred time) before, the easiest way to create small-ship content would simply be to outlaw big ships in certain systems.
Set it up so you can jump into a system, or jump your FC into a system, at the primary star, scan the nav-buoy, and it'll give you information about ship restrictions within the system.
Fly further than, say, 20Ls from the Primary in a "banned" ship and you risk being intercepted by System Security ships and gaining fines/bounties.
If you want to be an outlaw, go ahead and do it anyway.
If you want to remain lawful, make sure you're flying an approved ship.
Regarding credits, I think the biggest issue is that FDev have historically created a situation where there's something that is by far THE best way to earn credits, which means people who want credits farm the poop out of that thing... and then wail about how grindy and repetitive the game is.
What FDev need to do (IMO), is develop the whole "system state" thing so it has a meaningful effect on all sorts of things within a system.
You'd need to learn what states make certain activities profitable, and what other conditions make them especially profitable.
That way, becoming an "entrepreneur" can become a proper career in ED and it'd mean anybody who was an entrepreneur would need to be versatile, and thus reduce the wailing about repetition and grind.
It'd also be nice if FDev could develop some kind of RNG factor to simulate temporary profitable trends for certain things within a system.