Technology in this universe is a bit weird and feels like 1990's in space. I'm not really sure how to explain it but here is the wiki page that should answer your question.[url=http://cowboybebop.wikia.com/wiki/Technology] 
The main reason technology is this way is because of a catastrophe that occurred in the 21st century where the first astral gate exploded and almost shattered the moon which causes constant debris and radiation to fall to Earth. So while the necessity to relocate fueled the advancement of human colonization there wasn't a whole lot of advancement in other areas.