There have been efforts made to quantify number of protests based on some benchmarks of comparison, see A Global Standard for Reporting Conflict which summarizes such an approach as follows, emphasis mine:
propose an innovative conceptualisation of journalistic epistemology
in which ‘social truths’ can be identified as the basis for the
journalistic remit of factual reporting. If the world cannot be
accessed as it is, then it can be assembled as agreed – so long as
consensus on important meanings is kept under constant review. These
propositions are tested by extensive fieldwork in four countries:
Australia, the Philippines, South Africa and Mexico.
Digging a bit deeper into the article by Africa Check that was provided in the question, there are important clarifications about the "service delivery" protests than what the question legitimately (in my opinion) describes as a flurry of academic interest in 2012 that did indeed resemble a superficial "cause celebre" without much investigation or follow through. I perused the second link in the question, noting that it was written by an academic specializing in the field of "Social Change", from a publication with I am unfamiliar, with an alarming article title: A massive rebellion of the poor!
In contrast, Africa Check seems more well-balanced to me. It is not lightweight like Snopes, nor an obvious mouthpiece of the ruling government of South Africa.
Subsequent articles (right up through 2018) are quite critical of official leadership, cross-comparing protest frequency over time, and underlying causes, as well as identifying data reporting issues that tend to overestimate protest frequency and seriousness, see summary in SONA: More key claims fact checked.
The "30 protests a day" claim (as of approximately 2010 to 2012) in South Africa was incorrect. It was a gross overstatement over the next few years as well, see Police records ‘not a protest database’:
South Africa’s police service does not record “service-delivery”
protests. When the police are called out to monitor and control crowds, the
incidents are logged as “crowd-related incidents”. This category is
very wide and covers situations varying from sport matches to
electoral campaigns. Crowd-related incidents are furthermore divided
into “peaceful” or “unrest-related” events. However, this depends on
whether the police had to intervene and not on the crowd’s intention
or behaviour.
In the years 2012/3 2013/4 and 2014/5, peaceful incidents were 10,517/ 11,668/ 12,451. Unrest-related incidents were 1,882/ 1,907/ 2,289
The unrest-related incidents were nowhere near 30 per day in frequency! These findings were confirmed by the Crime and Justice Information and Analysis Hub at the Institute for Security Studies (ISS). The errors were likely due to news media confusing all crowd-related incidents that were recorded as being for protests:
"The ISS said their data, compiled from media reports between January
2013 and December 2015, showed that “the average was about 3 protests
and labour strikes a day”. But this referred to all kinds of protest,
not just those related to service delivery."
It does seem intuitive that protests are more frequent in South Africa than many other countries. "Events such as community uprisings, strikes by organised labour, and marches by churches" are not necessarily "diverse causes", but rather, plausible expressions of dissatisfaction and frustration due to the same root causes.
Note that many protests in South Africa are driven by vitally important concerns to those who participate, namely,
- increasing concern about corruption and crime,
According to Statistics South Africa’s 2013/14 Victims of Crime
Survey, which was published in December: “More than 70% of households
believed that corruption had increased during the period 2010–2013.
Over three-quarters of households thought people were involved in
corruption to get rich quickly (76.9%). Bribes were commonly paid in
order to speed up procedures (37.9%), followed by receiving better
treatment (23%) and to avoid traffic fines.” There are at least eleven agencies in South Africa that have a mandate to investigate corruption but a number of key anti-corruption institutions are in turmoil.
- unrest over labor and severe structural lack of jobs for those wanting to work, via Unemployment in South Africa, Explained (October 2017):
South Africa’s youth are in a dire situation. Recently released data
from Stats SA shows that nearly half (48.8%) of all people aged 15 to
24 are unemployed according to the narrow definition of unemployment.
According to the broad definition of unemployment (which includes
people that want to work but are not actively searching for a job as
they have lost hope, want to work but can’t find jobs in the area or
are unable to find work that requires their skills) 63.6% are
unemployed.
- diminishing living standards for many citizens (via WorldBank research, 2018, page xv):
South Africa is one of the most unequal countries in the world, and
that inequality has increased since the end of apartheid in 1994.
Also reason for protest, as of 2015, South Africa had the lowest life expectancy in the world:
South Africa’s life expectancy at birth was only 49.7 years of age in
2015. While South African men are expected to live a little longer (50.7 years), women fare worse, at 48.7 years. [The OECD estimated
life expectancy of 58 years on average, still the lowest in the OECD
and much lower than the average of 80 years in comparably wealthy
countries].