All of you are forgetting the theory that the Vasudans ARE the Ancients, or what's left of them at least.
I'm not strictly a fan of that in any case, rather not support it.
We don't know how long the Vasudans have been in space. It is likely they were forced there, in mass, earlier than Terrans (we still don't have any colonies on other worlds, it's likely the Vasudans would have in the same time frame), but I doubt on the whole it's much longer than the GTA. At the very least, the Vasudans probably achieved Inter-System subspace travel sooner as they seem to have more well established colonies than the Terrans do (considering they've been in space for something like 20 years when FS1 starts).
The real limitation is actually available resources. Vasuda Prime is NOT a pleasant place, so resources to conduct early space flight, or anything beyond a very primative technology base might have been a strain. 10,000 years might be how long it took them to develop what few resources they had to build a truly industrial civilization. But we can't really know, there just isn't enough information.