No I follow what you're saying. Make it available both ways.
My hesitation with connecting it to housing comes from some concern about how you would implement that sort of thing in the current setup. Not just visually but practically. Like, yeah the FC does have instanced access to the workshop and member's rooms, but they've mentioned before how adding things can cause a lot of server strain. We haven't gotten a slot increase for our yards (yet) for that very reason. If an FC were to have an airship landing or geenhouse outside, that could add to that strain. Likewise, if it's inside, that would be more to load inside on top of the unique decorating everyone does anyway.
Now, putting them into the area where the workshop and member rooms are could work (though I can't even imagine what that would look like off hand), but even that could have problems due to the sheer amount of options and data in one place. That's my concern.