Ignored within the USSR, because in those days (sixties, early seventies) computer access and power was even more limited there than it was in the West, where a monster mainframe did not pack as much power as the little thing on which you are reading this now. To the point that the more complex algorithms devised by Sukhotin had to be tested... by hand!
Ignored without, because... well, first of all, who reads Russian?
Second, I guess, because it was much more fun playing with affix-hopping and sundry Lego-style word manipulations of that ilk which had become all the rage in the US and were spreading to the West in the wake of the hula hoop. Why, we certainly do not need any spoilsports when we are having such a lovely time playing with tinfoil and butterfly wings thanks to good King Phunding!
Third, perhaps... what chance would you have stood of getting a University job, any University job, don't even think of tenure, investigating the brainchild of a Soviet researcher? Not Invented Here, the Knights of Nih would have said in your face, yeah, verily, even though thou hadst been an old woman. And fishy, very fishy, too. Art thou a KGB agent by any chance?