The universe created by Gene Roddenberry in the 1960s is home to a vast array of characters, locations, and even some of the biggest unsolved mysteries in science fiction history. The show has changed a lot since The Original Series, with varying degrees of respect to Roddenberry’s vision for the show. But at its core, it is still a program that focuses on people, and the relationships and issues between them. Each show has a varied and complex cast, from many walks of life and their own in-depth backstories. For the most part, they fulfilled their roles aboard their ships to the fullest. There are, however, exceptions, such as counselor Deanna Troi.
Troi is one of the main crew members and part of the protagonist circle in The Next Generation. She features in the majority of episodes, either as a side character or as the main focus of the episode. While her presence aboard the ship is always deemed important, there are some key facts about her that bring into question how much her abilities are really used. Troi is part human and part Betazoid, a race of humanoid aliens who have a natural affinity for telepathy. In the Star Trek universe, telepathy is something that is capable of any organic life form, humans included — but some races are more naturally adept at it than others. Troi, despite being only half Betazoid, possesses these abilities, and has a keen sense of the emotions within others.
On board the USS Enterprise D, her role is the ship's counselor. When taking into account her abilities, this is the perfect role for her. She would make an incredible counselor, and is shown to be through the show (with only some minor hiccups). When examining what the crew of the Enterprise do on a near-daily basis, it’s easy to forget that the vessel is not a military ship; rather, it is an exploration starship, going forth to explore new lands and civilizations.
Despite this fairly pacifistic mission statement, they do get into a lot of scrapes along the way, which makes the presence of a highly skilled counselor all the more important. The need for her services would seem to be in high regard from the plethora of traumatized crew members — after all, a high percentage of the crew were not Starfleet officers, but in fact civilians. However, Troi seems to spend the majority of her time not in her offices or quarters helping these people, but sitting on the bridge next to the captain. Troi spends about 90% of her time sitting beside Picard, waiting for an alien to come along so that her (granted, very useful) abilities would come in. She has no formal role on the bridge, and is not able to give orders or help like the rest of the crew there. Instead, she literally sits there and waits, unless of course there is a specific Troi-related plot point or narrative going on in a given episode.
When she does have a chance to help out, her main role is to detect or sense lifeforms, and gauge whenever or not there is something they are hiding. Most of the time, these moments seem glaringly obvious to audiences, with a shifty-looking, problematically stereotyped Ferengi on the view screen swearing he is telling the truth. It is important to note that Troi cannot actually read minds (if she could, things might get even more awkward with Riker), but rather gets a sense for what someone is thinking and feeling, making her insight into the situation based on a fairly accurate gut feeling.
If Troi were a full Betazoid, then perhaps her abilities would have been better suited for the bridge, being able to actually read the minds of those they are communicating or negotiating with. However, she does not possess this ability, and as such her time and actual skills would be much better suited elsewhere. This is not meant as a case to get rid of her, to banish her from the main action, as Deanna Troi is a delightful addition to the show. But there are various other important characters who don’t spend their time solely on the bridge; this is not the only place where protagonists can shine. The heroic visor-wearing engineer Geordi LaForge is considered a main character on TNG, and his time is spent where he is most useful: in engineering. The same goes for Dr. Crusher, the head doctor aboard the Enterprise, who spends her time in sickbay.
One of the reasons why the writers wanted Troi to constantly spend her time on the bridge is because that is where most of the action happens, and thus where most of the filming takes place. They wanted her to be seen, to be admired — partially as an incredibly dated sex symbol, but also to bring a bit of femininity to the otherwise male-dominated room.
Creating this diversity is great, but it would have been much better if her presence there was more important. It would have been more impactful if her role on the bridge was more active, much like Tasha Yar's before her untimely demise. As it stands, Deanna Troi spends the majority of the franchise sitting there offering fairly limited help to Picard, her otherwise important role aboard the ship being downgraded to eye candy.