To clarify, lets look at what baseload means. Lets take wikipedia's definition: > The baseload (also base load) is the minimum level of demand on an electrical grid over a span of time for example, one week...
Electricity demand varies over time (on various time scales). Electricity providers need to make sure that they can supply both the continuous demand (i.e. the lowest point of the noisy curve that is supply) and the fluctuations (using some sort of adjustable supplies). Traditionally it was cheaper to have some power plants run 24/7 at constant output power (e.g. your nuclear power plants), to supply the baseload and use more expensive adjustable sources, e.g. gas peakers to supply varying demand.
That is an economic decision, if gas peakers are cheaper than those plants running 24/7 you would never use them, because the variable sources give you much more flexibility.
With renewables we are in exactly this situations. Renewables give you varying supply, so essentially a noisy supply curve with some average and a minimum supply, given a sufficiently large grid that supply will not be zero and with enough build out, you will always have enough supply to cover baseload. Because renewables are so much cheaper than nuclear, economically you would always build more renewables to lift up your ability to supply baseload, moreover because (most) renewables are varying, you actually also create capability to supply the varying demand (something you can't do with a nuclear power plant).
So in short, intermittent renewables can supply baseload (in fact they are better at that then working as "peakers"). If they are much cheaper than nuclear (which has been the case for many countries) it makes more economic sense to build more renewables than large nuclear plants.
incidentally the wikipedia article talks about the fact that you can use intermittent sources for baseload just in the next sentence > This demand can be met by unvarying power plants,[2] dispatchable generation,[3] or by a collection of smaller intermittent energy sources,[4] depending on which approach has the best mix of low cost, availability and high reliability in any particular market.
So in short it is a myth that you require nuclear (or any large 24/7 power plant) for baseload. If renewables are significantly cheaper than nuclear, then it makes sense to invest in renewables to supply that baseload.