I know a number of airlines have experienced 'problems' with older guys struggling with the sheer volume of a type rating, or so they say. Don't shoot the messenger as I know there are exceptions to every rule and equally there will be younger guys who have failed type ratings and cost airlines money.
I think it comes to to mass generalisations; in their experience the younger guys are less of a risk factor because they tend to learn quicker.
Anyhow, keep plugging away and don't set your sights too high for the first break.
PP