If you own the product to-be-built and it is your startup, then you need to think like a businessman and that includes listening to customers. But if you work

If you own the product to-be-built and it is your startup, then you need to think like a businessman and that includes listening to customers. But if you work as a salaried employee or contractor - lets face it - you really in a position to care more about your personal income and care less about customers who will be buying the product you don't directly benefit from. You better realize that you can and will be let go on a minute's notice and no one is going to drop a tear that you're no longer there. And hence your survival depends on convincing the management to build the product using technologies that you can benefit from by knowing them, just in case you decided to quit or will be let go. Even though above may sounds selfish - this does not mean your personal interests are not aligned with the company you're working for. Quite often the opposite - and quite often it's win win for everyone.