Imagine you're opening a pizza restaurant but are hesitant to invest in quality ingredients to make your pizza the best in town. So instead of making your own pizza, you start out selling frozen pizzas which you think are 'good enough' to sell until you can afford to buy quality ingredients to make better pizzas. The problem with this is that first impressions for a new business are everything! Someone who gets a mediocre product is unlikely to come back.
The prints from print on demand companies only last 30-40 washes! Even if you have the best designs in the world, you can't expect people will come back after experiencing these low quality frozen pizza prints.