Cape Kennedy sits at 28.4 degrees. It is the optimal flight path.
What has the location of the launch site have to do with the inclination of the orbit> They could select any orbit they would like.
They can select any orbit with an inclination of 28.4 degrees or higher. Well, actually, they
could select any orbit they like, but if the inclination is less than 28.4 degrees, then there will be a large cost in fuel to achieve it.
Let's take an orbit with an inclination of zero as an example. Such an orbit is above the equator. So if you launch from Cape Canaveral, how do you achieve an orbit with an inclination of zero? The rocket takes off at 28.4 degrees, then it has to travel south to get to the equator. That's a long way - the rocket will be in orbit by then. So if it just coasts to the equator, then it will continue south to at least 28.4 degrees south. If the rocket was launched straight east (or west, for that matter, although there are reasons not to do that) from Cape Canaveral, then 28.4 degrees south will be the southernmost point of the orbit (farther south than Rio de Janeiro, but not quite as far south as Buenos Aires). If they launched it either southward or northward, then the most southerly latitude the orbit reaches will be more south than 28.4 degrees.
So if you don't do anything to change the orbit after launch, the spacecraft will be oscillating north and south of the equator each orbit, by at least 28.4 degrees (and possibly more, depending on the direction of the rocket when it was launched).
To get into an orbit over the equator, there would have to be a course correction when the craft reaches the equator, to stop the southward motion. This can be done in theory, but you're going to need enough fuel to do it. And the amount of fuel will be a lot.
So, yes, in theory, you can achieve any orbit you like launching from Cape Canaveral, but if the inclination is less than 28.4 degrees, you have to carry enough fuel to do the course correction (which will cut down on how much payload you can carry, and possibly exceed the carrying capacity of your craft), and you need to have an engine that can do the burn. It's hard enough and expensive enough to get a spacecraft into orbit, that you don't want to choose suboptimal orbits (like having an inclination of less than the latitude of your launch site) unless you really need to.
The Soviet Union (and now the Russian Space Agency) were at something of a disadvantage in this regard, since their launch site is so far north. This limited the orbits they could easily achieve. (There is another reason south is better as well.) There's a reason the US launch site is in Florida, and not in North Dakota or Alaska. It's the same reason the Soviet (now Russian) launch site is as far south as they could make it, and the European Space Agency launches from the northern part of South America.
Cape canaveral is 28.4 degrees from what? The equator?
Yes, the equator.