LBJ is consistently ranked among the upper echelon of Presidents on the all-time lists by both liberal and conservative historians. No lower than the upper third, or about 15th or so, in any legitimate look back at the Presidents of our nation, that I've ever seen. Higher than that in most.
Not defending him per se, or claiming his presidency was the bomb or anything, but he did some important things, especially in regards to civil rights, and he did them in one of the most chaotic periods of this country's existence, and after unimaginable tragedy. That counts for something.
Put it this way, he was an inarguably better President than any republican who's held the office since he left, with the possible exception of Reagan. Nixon, Ford, Bush, and W., were all disasters - Watergate, War on Drugs/DEA, pardons a President that's a criminal for a coverup, massive recession, Desert Storm fails to remove Saddam, 9/11, Afghanistan War (longest running in US history - no clear exit ahead), Iraq War (creation of ISIS), housing crisis nearly brings down global economy, massive recession/barely averted New Great Depression...and those are just the big ones.
Take a look at the terms of LBJ, Clinton and Obama comparatively, really be honest with yourself, and answer the question - were we not better off economically, fiscally, and as a society overall, than at any other time during the Nixon, Ford, Bush, and W. administrations? (We can leave Carter and Reagan out of this...for now)