Tricky one.
Here’s a bit of text based art.

It’s drawn in a quite crude style. That indicates that it’s based on raw, unmediated emotions, which is a high scoring feature when it coms to art. It lacks depth, nuance, ambiguity and technical skill though, which are also high scorers in the art world.
So maybe text based art tends to be produced by artists who lack depth, nuance or technical skill, so they sensibly avoid creating art that needs those qualities (just as an artist who can’t capture a human likeness would shy away from portraiture). They may or may not possess raw, unmediated emotions, depending on what type of text based art they produce.
In text art the message in the words is important. In the example above the artist is saying “Look – I’m not a bigot”. The audience sees the work and thinks “That’s good, because I’m not a bigot either. This artist is a good person whom I identify with”. If the words in the piece had been “Sod off you immigrant” the typical art gallery audience would probably reject the piece altogether, dismissing it as not a piece of art but as the ranting of a bigot (and as I’ve just mentioned, art audiences like to think that they’re not bigots).
This shows a fundamental difference between text art and other forms of visual art. With landscape painting, for example, the difference between good and bad art is maybe measured in factors such as the subtle depiction in paint of the play of light across a hillside, with text art it’s measured in the message.