The essence of the hierarchy is the notion of “pre-potency”,
which means that you are not going to be motivated by any
higher-level needs until your lower-level ones have been
satisfied. Note however, that pre-potency only makes sense
over a substantial time-scale. I ate a good breakfast this
morning, but I shall be hungry again tonight: thus I may
become concerned about Physiological needs again then. But
if I “know where the next meal is coming from”, concern
about meeting those needs will not be a great motivator.
Comment
Where the model is useful is
in identifying individuals who get stuck on the lower levels,
and who because of early insecurity or later trauma, cannot
afford to be concerned with the higher levels: but this
is chiefly relevant to mental health professionals rather
than teachers. It also, of course, draws attention to how
very basic problems—such as being too hot or too cold—can
inhibit motivation to learn at higher levels, but we did
not really need Maslow to tell us that.
The major difficulty with Maslow is that although
his hierarchy makes sense in general terms — if I am pre-occupied
with physical needs, I am not usually going to be interested
in self-esteem needs, for example — there are equally many
occasions on which it does not hold good. It is excessively
individualistic, and does not allow for altruism. And although
most of Motivation and Personality is about defining
“self-actualisation”, he never really succeeds in doing
it. It is one of those models in which there is actually
less to it than meets the eye!
A similar point is made in Herzberg's
“motivational hygiene” theory, according to which
demotivators (or "hygiene factors") have to be reduced as well
as motivators (or incentives) increased, to develop positive
motivation (Herzberg 1966):

(Note that the factors shown are
for illustration only: the balance may be very different
for any particular person and/or situation)
Tha analogy here is with the tuning of a radio: turning up
the volume (increasing the motivators) on a badly-tuned
station will only increase the noise level as well, and not
the clarity of the reception. Tuning out the interference is
the major task.
In practical terms, most courses are beset with
de-motivators of one sort or another, ranging from unhelpful
administrative procedures and poor communication, to teachers'
distracting mannerisms: infuriatingly, some of those are often
beyond our control. They count most at the start of the course,
before the positive motivators have had time to kick in, and
when students may already be rather anxious.
Even so, everyone in a learning group is motivated to do
something: the question is whether the motivation
fits with the requirements of the programme. The issue is not an
absolute one about motivation, it is about our assumption that
people ought to be motivated to learn what we want them to. (See
“What is taught and what is Learned”)