It doesn't MATTER. As long as a mapper exists, maps are editable without hex editing it like an insane monkey. Scripts can always be sorted out later. Research can be done and a mapper made on gen 5, script compiler or no script compiler. I'm pointing out that there is no arbitrary reason that gen 4 should be done first - especially since gen 5 has a better engine.
We are getting there, good sir. Gen 4 is first priority only because Gen 5 is based on Gen 4, thus we're already trying to do Gen 5 but we don't have any skills. There is already a viewer for Gen 5 so we're not trying to exclude Gen 5 from the picture here. We're merely trying to understand the hard concepts of Geometry commands (do YOU know what 00 00 00 40 01 00 00 00 means? Me neither.) and stuff, so rest your butt and we'll get to Gen 5 in no time.
In fact, we all want Gen 5. I want Gen 5, in fact. If I had a freaking choice, Gen 4 is waaaaaay over, and I would just focus on Gen 5.
I see what you're saying, but take a look. What happened before Gen 3 was hacked so extensively? Gen 2. And before that, Gen 1. You couldn't just go to a forum in 2004 and demand that a mapping tool be made right then, on the spot. Now look, seven years later. What do you get? A nice and polished Advanced-Map, not some crappy tool someone threw together in two weeks that doesn't even work.
That being said, hacking it is even EASIER because you don't have to deal with offsets, and the sections are even marked out for you in the very beginning, in a fashionable order. However, there is one part (the BMD files) we need to figure out before we jump to developing tools for Gen 5 and leave Gen 4 behind in the dust.
Also, you should try hex editing. Oh, the things you learn.
And as for a scripting tool, there is PPRE, so now there is a reason to work on mapping.