No. GW Bush’s “grades” did not get him into Harvard, just as the “waiting line” did not get him into the National Guard during Vietnam. His father, GW Bush, was a Yale legacy who got him into Yale; from there, he could do what he wanted. The Bush family has been a political disaster for the Republican Party and the nation, and in my view, GW is dumb as mud, although he continues in the family tradition of kissing up to the political left while trashing conservatives every chance they get except when they need their votes at election time.
I don't agree with the Bushes' politics, but in my view, your opinions are based on faulty info.
Do you know GWB personally, or based your opinion on what you've read? Dan Rather maybe?