Because debating things is what people do and should do. Also, the scientific system in the Soviet Union does not automatically equate to Stalinism.
On of the closing paragraphs more or less answers your question:
"To avert any misunderstanding: I am not defending the Soviet Science System; I am describing it. There was a great deal of shoddy work, rent-seeking and suffering within that system. But there was also extremely good work, and the latter was a product of the system that engendered the former. That’s the paradox that comes from looking at any science system: it wouldn’t be a system at all if it didn’t, in some sense, work."
On of the closing paragraphs more or less answers your question:
"To avert any misunderstanding: I am not defending the Soviet Science System; I am describing it. There was a great deal of shoddy work, rent-seeking and suffering within that system. But there was also extremely good work, and the latter was a product of the system that engendered the former. That’s the paradox that comes from looking at any science system: it wouldn’t be a system at all if it didn’t, in some sense, work."