Why are hen chicken wings are tougher than regular chicken wings at the store?

Hens are much older than the chickens grown for meat. The older the animal is when slaughtered, the tougher the meat.

Poulets or capons for meat production usually are slaughtered at around six weeks to three months of age.

Hens are slaughtered for stew and soup at the end of their prime breeding age, around one and a half years for egg layers, or 2 years for hens that produce eggs for meat birds.