That sounds about right. JFK was largely a do-nothing President remembered fondly mostly because he took a good picture and looked the part. LBJ did more in his first 100 days as president than JFK did in his entire political career. JFK did almost nothing for Civil Rights which was the issue of his age and it was not a priority for him. He was only interested in foreign affairs. Absent the assassination at his youthful age, he would be remembered as a mediocre president.
The historian Richard Reeves in "President Kennedy: Profile of Power" (a really good book on his presidency):
"Kennedy was decisive, though he never made a decision until he had to, and then invariably he chose the most moderate of available options. His most consistent mistake in governing, as opposed to politics, was thinking that power could be hoarded for use at the right moment - but moments and conditions defied reason. He had little ideology beyond anti-Communist and faith in active, pragmatic government...What convictions he did have, on nuclear proliferation or civil rights or the use of military power, he was often willing to suspend, particularly if that avoided confrontation with Congress or the risk of being called soft."
I do think he deserves credit for normalizing relations with the USSR, for abandoning Eisenhower's first use policy and mitigating the possibility of a US/USSR conflict. He recognized, unlike a lot of people around him (not just the military), that a nuclear war was simply unthinkable, that it couldn't be limited or constrained.
It's remarkable that many conspiracy believers - the Stone/Garrison crowd for example - promote JFK as a Arthurian/great leader who was going to drastically change America for the better - not just in Vietnam or in foreign policy but domestically as well - and it was for this that he was struck down by the powerful forces he threatened. Then along comes LBJ who did far more to change America than JFK ever dreamed off. So these elements killed JFK to stop this change and then LBJ comes along and does all of the things, and more, that JFK wanted to do? It makes no sense but in conspiracy world it doesn't have to make sense; it just has to help promote the idea of a conspiracy.
The Kennedys simply didn't know how to pass legislation much less show interest in it. Working the Congress, making deals, cajoling and threatening members. LBJ knew how to do all of that; he acted quickly after the assassination to use the death of JFK to promote civil rights. Then after his landslide election he acted quickly to pass the Great Society. He knew he had to use that power to act immediately. JFK, as Reeves says above, wasn't interested in that.