Do I think primary teachers work hard and long hours - yes.
Do I think that is also the case for many, many other workers in our current economy - absolutely.
Do I think all teachers work the same hours - no.
IME, primary teachers work longer hours on a day-in, day-out basis, but secondaer teachers have bigger peaks and troughs. However, I would also say that what is 'acceptable' in terms of marking, differentiation etc in secondary would NOT be acceptable in many primaries, and that contributes to the difference. I would be in trouble if a child's book was picked up and had more than 1 day of unmarked work (an occasional 1 day is OK, but 2 days would be a significant black mark). My DS's books, even in really critical subjects such as maths and englisgh, often go unmarked for a couple of weeks at a time, in some subjects for much longer than that.
Also some teachers are, for a variety of reaseons, shorter / longer hours workers - it will depend on the school (some do re-use plans, others do not, and like all workplaces each has its own 'culture' of presenteeism or work hard / play hard )
Do I think that teaching has a 'uniquely hard time' in the press, public opinion and politically - no. But i do think it s there as a more constant, low level 'drip, drip', whereas other professions / jobs have their time in the limelight and then fade away for a bit.