A friend of mine - a very pleasant, hardworking but not particularly assertive young woman - was shamelessly bullied by her employer. In the end her confidence was so undermined and she was so distraught that she just gave in her notice with no job to go to. I was going to support her in claiming "constructive dismissal" but as it is known to be quite difficult to prove, she felt she could not risk losing the Tribunal fee and so did nothing.
Fortunately, she now has another job so it turned out all right in the end.
Although there are "vexatious litigants" and they should, in my opinion, be dealt with more firmly, I believe that the vast majority of applicants to the Tribunal are genuine.