developers will work on whatever developers want to work on.
I'm actively avoiding working on Raiden 2 and some PGM stuff for MAME right now because some idiot is spamming MAMEdev and my mail account every week about them (it was multiple times a day, every day for the previous 6 months)
I don't think you understand the sheer amount of work involving in emulating the games you mention, the complexity of the hardware. Either that, or you're trolling, because your posts read either as completely uninformed and unwilling to do any research of your own to actually understand the nature of emulation, or as a troll just trying to annoy the developers with requests.
Taito F3 is a VERY complex system in terms of the video, MAME doesn't even get it correct at the moment, and doing so will probably make the driver a lot slower. It would be an enormous amount of code for FBA devs to write, and in the end they'd just end up replicating all the MAME bugs too because the rest will probably require extensive hardware tests.
Desyncs can be practically impossible to track down, because you never know exactly when they're going to happen and an enormous amount of factors can be involved.
Things like Naomi and Atomiswave are outside the scope of the project entirely, likewise PSX based stuff.
Maybe MAME makes these things look easy, but the number of hours of work put in there is astronomical, even just trying to copy and paste the drivers for the more advanced systems would be an insanely difficult task for FBA because a lot of the backend / framework MAME has simply doesn't exist. If you simply copy all that too, then you have nothing but a copy of MAME, at which point you may as well just use MAME.
The sheer stupidity of some of the requests here, and on barry's site are nearly unbelievable. People have dedicated YEARS to emulating some of the systems mentioned, and yet people expect FBA devs to simply conjure something up out of nothing in a few days?