If force sensitivity is a recessive trait, it would be possible to be force sensitive but not have force sensitive parents and vice versa.
If force sensitivity was a recessive trait, all kids of two Jedi would have this ability, too. And kids of non-Jedi would have an incredibly small chance to be force sensitive. This would make it almost mandatory that Jedi have families and children, otherwise the order quickly runs out of members.
Not necessarily. If Force sensitivity is recessive, two parents who are not Force sensitive could conceive an offspring who is Force sensitive provided that both of the parents have one dominant gene and one recessive gene. Moreover, not everyone who is Force sensitive is recruited into the Jedi Order.
Furthermore, there is another thing to consider: if Jedi had families, George Lucas would have probably shown at least some of those families on screen. That would probably mean many more child actors in the Prequel Trilogy.