More utter nonsense.
It all depends on what other filters you have (carbon, sand, ceramic, paper, etc) prior to the resin filter. Your resin filter may need backflushing more often if it's getting clogged unnecessarily because you haven't got the correct sequence of filter material. If you're 'reactivating' the resin unnecessarily every time you backflush it you are not only wasting a lot of money buying salt for no reason but you are also unnecessarily damaging the area where your salt water backflush is dumped.
A responsible and informed manufacturer will ensure that you at least know what sequence of filters you need for your particular circumstances. An uninformed and irresponsible supplier will either not know or not care if your system is operating effectively and efficiently as long as you buy their rubbish and/or boost their ego.