The reasons doing a startup are totally irrelevant. For some it's money, for other power, status, passion or whatever. It's not important why you do a startup. These are just drivers and they are good because they push you to start—push you beyond your boundaries. Are these the right reasons? Nobody cares.
It's important just to do something, to start and to carry on.
Even if it will get very hard it's the most satisfying experience you'll never regret—you learn, you do, you make decisions. Looking back every single day I spent as an employee was a waste of time.
Knowing why you do something, puts the soul in your work. Without it, it's just work. I refuse to believe life is simply a long grind of do-ing with an eventual not-doing as the reward. No. Love for your work, passion for what you do, is the thing that fathers beautiful things. It's the thing that makes great companies work. Heck, it's the thing that makes life work.
You list power, status or passion as possible why's. Which leads me to believe you misunderstand what true motivation really is. Wanting to create something beautiful for the sake of beauty, to contribute in a meaningful way, to add instead of substract. These are transcending human endeavours. Status, power, money; just side-effects to the medicin that is purpose.
Even you've had a reason for pushing yourself to create. Perhaps it was that in the back of your mind you believed that you deserved to live a better lifestyle.
It's your vision of the future that moves you to act. The belief that things can be different, and that you are able to effect that difference. Having a why isn't important?
Having a why is the goal.
It's interesting that you use the word transcend. I believe its 100% appropriate in this case.
Money, power, passion, and status are wholly human motivations available to anyone. The desire for beauty for the sake of beauty really does transcend the far more practical goals of majority of people, and places as an ideal something completely abstract.
Now, I wouldn't call it "true" motivation because that'd lead us down the angle of a "no true scotsman" discussion.
Even if you do a startup for 'wrong' reasons like chasing money and fame at least you did something, hell you learned something and made mistakes. That's what's all about! What's the alternative? Staying employed and missing all your life?
It's the experience, it's the way and not the goal.
Discussions around doing or not doing a startup are just excuses for oneself to not start something because it's not the right idea, not the right time, not the right co-founders, not the right setup and suddenly these people are 50, missed everything and are full of fear loosing their crappy job.
Definitely not against building a startup. However instead of building another photo sharing social media site why not build a better way to raise money for charity, or solve a difficult problem in your field of expertise.
Why kill yourself for five years on a problem or pursuit you are not 100% passionate about?
It's important just to do something, to start and to carry on.
Even if it will get very hard it's the most satisfying experience you'll never regret—you learn, you do, you make decisions. Looking back every single day I spent as an employee was a waste of time.