That's very interesting, but it's from a small charter airline, not a "real"
airline, and one that has a ridiculous European-like baggage limit of 44 lbs
total.  Real airlines have baggage limits of 50 or 70 lbs per bag, two bags
per passenger.

Besides, you said:

Perhaps it was the "most airlines" part that was lost in translation.  As in
"Most airlines give an extra baggage allowance".  That could really screw
someone up if they actually believed it, almost as bad as telling people
that they can fly with their hair still wet.

Air Canada allows two 70 lb bags.  Scuba gear will be accepted in lieu of
one of the two bags.

http://www.aircanada.com/en/travelinfo/airport/baggage/checked.html#r1s0

Continental allows two 50 lb or 70 lb bags, depending on the final
destination.  A dive bag will be included as one of the two bags.

Etc.

P.S.  Travel agents lie when they don't know the answer.  Airline
restrictions change often, can be complex, and vary widely among the
hundreds of airlines in the business.  When in doubt, do not call your
travel agent because "my travel agent said so" is not considered a valid
excuse and you will be subject to potentially expensive surcharges or even
the risk of them denying some of your luggage altogether.

One example of this:  Coming back from a group charter in the Galapagos, we
were confronted by a luggage "embargo" in Ecuador.  Continental absolutely
refused to take my overweight bag unless I removed 6 kg.  I have no idea how
my formerly 70 lb bag got 6 kg too heavy, but it was not because I was
smuggling large amounts of cocaine.  Bringing a full set of open circuit
gear, including thick wetsuit, along with a Draeger rebreather and
absorbent, and a camera housing and twin strobes, plus a few articles of
clothing, does not make one a light traveler.  Yet I had no problem getting
down there by paying only an extra piece charge.  On the way back,
Continental said no.  I opened my wallet and prepared to shed lots of cash
for overweight and extra piece charges, but they again said no.  I would
have to remove 6 kg of luggage and leave it in Ecuador.

I began to weigh my options, as the hostile line of cocaine-smuggling
Ecuadorians grew behind me.  There was no fitting it in my carry-on because
that was already over-stuffed.  I could ditch the T-shirts I bought, or
perhaps my pony bottle, my worn booties, the unused aborbent I was bringing
back, what?  The travel agent who arranged the group travel had never warned
us about embargos.  Who would have thought to ask about an embargo?
Fortunately we resolved the situation.  The airline had delayed the luggage
of several in our group by three days, which had really screwed up our
charter itinerary, so when confronted with this faux pas by the group
leader, the airline finally relented and accepted my bags and didn't even
surcharge me.  When I returned, I reviewed the Continental website and found
some cryptic language about embargoes from certain South American countries
that might have prompted me to ask further.  When in doubt or even when not
in doubt, check the website and/or call the airline itself.  Screw travel
agents.