The thing is, SEGA is not in a position to spend massive amounts of money on R&D like they did back in the 90's.
In the 90's SEGA was a dominate force, consoles rarely were able to match their Arcade counterparts, and SEGA also had a Tri-Region arcade industry to help cover the costs of the hardware.
Flash to the late 90's and early 2000's and its a different picture. Their financial loss in the console market and the decline of arcade revenue due to more sophisticated home consoles that are able to for the most part match arcades in terms of eye candy. I believe it was 2 years ago that SEGA was finally able to turn around and pull a full profit instead of losing money, and as such they are focusing on what they do best, and thats software.
Believe me, I love SEGA, console and arcade fanboy for life, but as you saw in those screenshots of VF5 and After Burner their eye candy is hardly anything to scoff at. Sure its not cutting edge, but when you have a company like SEGA creating software for any type of hardware, your bound to have something special. Those graphics would not, repeat NOT be possible on the PC since there are countless configurations to account for. Thats the similiarity that the current Lindbergh boards have with the old Naomi/Model1,2,3 boards. Consistancy, same hardware much like a console means you can squeeze a huge amount of performance from a machine.
IMO Its not lowend, its not high-end, its incredible software development that makes the hardware, and they aren't spending millions upon millions of dollars on it, they save money on the hardware and rake in the money from people paying to play their amazing software.