"Life isn't fair." "Life is a crap shoot." "Some people get all the breaks." "It's not what you know, it's who you know." "The secret to success is being at the right place at the right time."
These are some of the common clichés that crop up when, despite our efforts, success eludes us. Although telling ourselves these things places the blame for our failures on external forces beyond our control and therefore makes us feel less shamed and not quite so bad about ourselves, they actually disempower us.
They strengthen the concept that one can work hard and end up with nothing to show for it, which tends to generate feelings of depression, anxiety, frustration, anger and demoralization, all of which can dampen our energy, our enthusiasm, our drive and our motivation to continue trying.
Consequently, telling ourselves messages that reinforce our sense of victimhood are more counterproductive than helpful, particularly so when they contribute to our avoiding taking responsibility for our failures.
For example, if there are things we are doing that are mistakes and/or self-sabotaging, and we tell ourselves that it's just bad luck, then we won't look at our own thoughts and actions to see if there's something we can correct.