I think this just goes to show that quality cruise lines, such as NCL and others will work to accommodate those with disabilities as a mater of good buisness. Getting the courts involved will only hurt the smaller lines. Those lines that can't, or won't make these changes will eventually suffer.
One can not equate "discrimination" of disabilities with racial discrimination in this case. Racial or other ethnic discrimination is an emotion and in no way involves prohibative, costly modifications to the ship which changing the lack of handicapped access in many cases will.
My humble opinion would be for those involved in this suit to spend their money on another cruise line which does accommodate their needs rather than bolster attorneys pockets.