In Conspiracy, Starfleet seems surprised to see the Enterprise in the Sol system, and they make a big deal out of the fact that the ship has returned to Earth, well outside of it's mission parameters. Which sits uneasily with the later seasons, where it seemed like the Enterprise was always coming home to Earth, and it's mission seemed to see it spending most of it's time within already well explored areas (Romulan and Klingon borders) rather than "exploring strange new worlds".The original concept was the Enterprise embarking on a 10-20 year deep space voyage and so the idea of families aboard had some rationale to it. Indeed in some of the early episodes there are vague references to "a long voyage ahead" and "our path lies outward" or something to that effect. But the moment they started having family members (like Llwaxana Troi) and others visiting aboard and having the ship return to Earth so easily the families concept was completely undermined.

Of course, an in-universe explanation would probably be that the ship's mission parameters changed. Perhaps when the Romulans came out of retirement at the end of S1, Starfleet figured that they should reprioritise and make sure they kept the fleet fairly close to UFP home base.