I travelled globally for business, over 80 countries.I for one am going places with my travel rods in hand and saying screw you to airlines that gouge fishermen.
Would often pack 3 piece rods or 4 piece pack flyrods,
if I thought I would have a chance at some fishing while on a trip.
These were good mostly for "putzing around" type fishing,
and would rarely be the right tools for a more serious trip.
I would pack these rods diagonally in my checked bag.
For any serious type trip while on business,
or a dedicated fishing travel trip, a rod tube is necessary.
Even if there were plenty of 3 piece rods to choose from,
for a dedicated fishing trip where you need 4-5 or more rods usually,
you're not going to be able to bundle them up and take as carry on.
The current trend with the airlines is to more stringley enforce
carryon size rules, and soon weight as well.
Trick is to choose an airline that does not penalize you
for sporting goods.
Those that do not, generally allow up to 60" in length,
and there is no surcharge, it counts as a bag.
Solves the gouging problem.
To support Benwah's comments,
the tackle retailers that market their own brand
of fishing rods,
to produce a new rod,
their miimum required order is usually 50-100 rods from their manunfacture.
That represents a 7/10k or 15/20k investment,
which is not a lot of money in this game,
and yet no one has taken the plunge.
They all read these boards,
and many of them travel extensively.
ps. the only smaller market I can think
of would be building pack rods for traveling surf fishermen