Your T-Shirt Sucks is a fairly rude opinion for a T-shirt to have. It is also an awkward position for a T-shirt to defend.
The first reading is quick. Somebody sees the words, looks down at what they are wearing, and gets the apparent target. But the message has arrived on another T-shirt. The critic is standing in exactly the same category as the thing it is criticizing.
That is where the design gets more interesting than a simple insult. It sets up a small argument and makes the speaker part of the problem. The shirt can point at everything around it, but it cannot step outside the joke.
A critic made of the same material
A statement tee asks a few printed words to carry an opinion into a room. Sometimes the opinion is serious. Sometimes it is an admission, a warning or a joke. Your T-Shirt Sucks turns that whole arrangement back on itself. A message on clothing has decided that messages on clothing are available for criticism.
There is a good amount of cheek in selling that idea as another graphic tee. Blacksunset makes shirts with words and pictures on them; this one gives the collection a chance to laugh at its own format. The joke works better when its maker is standing inside it.
The sentence also leaves its accusation wonderfully unsupported. It provides no explanation of what makes the other shirt bad. No judgment of color, print or fit follows. The confidence is enormous and the evidence consists entirely of four words. That imbalance gives the line some of its dry humor.
The trouble with your
The most useful word here may be your. Its target changes with whoever is reading. Seen by another person, the phrase points outward. Seen by the wearer in a mirror, it becomes a slightly inconvenient piece of feedback. The shirt has not changed its mind; the reading position has changed.
That small shift keeps the joke from settling comfortably into superiority. The wearer can enjoy the provocation while remaining available as its next target. It is hard to look completely above the situation while wearing an example of it.
This T-Shirt Identifies As Black gives clothing another unnecessary speaking part. That shirt describes itself with great seriousness. This one moves directly into criticism, with roughly the same level of authority.
And Do Not Read This also needs the reader to complete its joke. The words alone set up the mechanism; the moment someone reads them is when the awkwardness arrives.
Your T-Shirt Sucks keeps that mechanism simple. A short accusation, an obvious contradiction and no reliable place for the accusing shirt to hide. It is allowed to have an opinion. Everyone else is allowed to notice what it is wearing.