They are resenting the fact that you are an outlier, a 'free spirit' and even if you had succeeded in your startup, they wouldn't see the relevance of that succ

They are resenting the fact that you are an outlier, a 'free spirit' and even if you had succeeded in your startup, they wouldn't see the relevance of that success to a (seemingly boring) desk job. UK companies read a lot 'between the lines' and it can be frustrating to find your strengths noted as weaknesses. Try not letting that affect your own perceptions.