Its actually very true. Most programs today with all their fancy code are encrypted and cannot be edited sometimes even external mods are not accepted.
That's a core design thing, it has nothing whatsoever to do with the language in which the code is written. You can write a completely open, totally moddable engine in whatever language you want, just as you can write a completely locked-down one. Now, FS2 started off rather mod friendly, and we have done our best to make it even more accessible over the years, but it's not due to the language we use.
Which, for the record, is a sometimes horrifying mix of C++ and old-school C.
Plus, sometimes the editing programs cost money or they suck ass. Freespace, because of its simplicity can be easily modified, not only on a mission/campaign basis, but also Volition was full of awesome and gave us FS's source code.
Never, ever make the mistake of assuming that just because it's easy to build custom stuff on FSO, it's just as easy on the inside. When I said that it takes a good coder 2 to 4 months of concentrated work to get his bearings in the source, I wasn't kidding. The greatest hurdle for new guys is the lack of formal documentation and design documents; it's pretty much
RTFS from top to bottom.
Having a more understandable SRC, it can easily be modified at a code level. Also, the Descent-Network gave us: The Descent Manager Series. Awesome stuff.
Again, having the source and doing useful stuff with it are two very different things. There are a lot of things we have to keep in mind when working on the code, not the least of which are knock-on effects coming from the insane level of interconnectedness in the engine.
Freespace's coding for things that happen in missions, tables and suchlike are simple text files in universal ASCII (aka UTF-8) which in fact is the only text you can use for C++, FS's programing language.
Wrong. We use ANSI encoding, no UTF here, move along. What that has to do with C is something I do not know. (We could use EBCDIC and still be just fine)
FACT: Freespace, yes the original FS, is so awesome, that if you try to deprive it of your multiple cored CPU, it will actually slow down. No I'm not kidding. I had to set FS for Win95 compatibility mode, and XP only gave it one core, slowing down the game to a crawl. Setting FS to use both my CPU's cores fixed that problem.
FACT: FreeSpace doesn't know squat about cores. It's a single-thread application; it won't ever utilize more than one core. same goes for FS2. As for the slowdown you experienced, I guess XP tried to run it on the same core as the OS and other threads, thus causing slowdowns.
FSO is hardcoded to use Core 1 if there is more than a single core available. If you run it on a 2.2GHz Quad core you'll get the same performance as you'd expect from a 2.2GHz Dual Core.