It is not invalid, it just does not belong wholly to you. Also your parents paid significantly (adjusted for inflation) higher taxes than you or I do now, taxes that were used for our education and the infastucture that allowed them to provide for us and our current sucsess.
Look at it like this...
You (Todd) are very talented firearms instructor with a series of excellent classes and a website and forum to support the community. You worked hard to develop your skills, your curriculum and your following. You deserve all the credit and income from these endevours.
However, you did not invent:
The bullet, the firearm, training or teaching, the internet (that was Al Gore
or the software that your website and this forum runs on.
So to say that you could have gotten to this place solely on your own is not credible.
You were lucky enugh to be born into a home, community and a country that allowed you to pursue these endevours, and you could not have achieved them without the support of your parents, teachers, community, collegues, software developers and the internet.
So the point Obama's making is again "you didn't build that". "That" being the opportunities that afforded you your business success.
Now, where I think the real philosophical divide is, is who you believe the government should be trying to create those opportunities for? Those that have sucsess already or those in need of opportuinites for sucsess in the first place.