If the text is an obvious distraction and degrades the wall it is generally rejected.
Text graphics, like other elements, can add to the 'style' of the wall....take Misery's 'Nijikon Fetchi' for example....[I know this one because of my recent 'STEP theme]. Without the text 'elements' the wall would be somewhat denuded.
The major 'no-no' is strident web addresses emblazonned across the guts of the wall.....or the use of a profusion of font styles...