It's certainly easier to recycle props and clothing by giving the future a contemporary look--machineguns and coveralls--than it is to create from whole cloth a very different aesthetic that must be realized.
It's not only easier, but advantageous because people in the main do have a preference for things which
appear real. The answer to "what do we buy ourselves by creating a futuristic or alien aesthetic" is usually "hopefully a more devoted audience, but almost certainly a smaller one."
To build a world from scratch but do it plausibly enough to reduce the "gimme a break" factor - for want of a more elegant term - for many in the potential audience requires a huge financial investment. Lucas can do it, Cameron can do it, Abrams did it for his Star Trek movie where it made sense to him to do so...but it carries a price tag in the hundreds of millions.
One reason among many that
Babylon 5 may not have reached a larger audience is that the producers seemed to reason that given a certain level of creative effort in the visualization of their universe - something on a par with Trek TOS, in most respects, falling short of that in some and exceeding it in others - that skiffy fans would make the imaginative leap, the commitment to fill in the blanks for themselves that they had made with Trek. Only that assumption made the idea of doing B5 on a limited TV budget plausible at all, and it did work - just for not an enormous number of people. The folks that like such things like them a
lot, but most people change the channel.