nyccc2, that is true but ONLY for mortgages and car loans.
It does not apply to credit cards, in any way.
If you apply for 10 cc's, you will have 10 hard inqs appear on your CR. And THAT alone may drop your scores 30-70 points. Maybe more.
And don't forget, the more new cards you add, the shorter your credit history becomes. And length of credit history is 15% of your FICO score.
Look at the pie chart in the Credit Education section of the myFiCO home page.