"However, I have seen many times that some of the people who gather together to discuss these things don't enjoy the long talks about it, they are just doing it to please their friends who are gathered with them. In such a case it would seem that there would be a concern of Issur for those who don't enjoy it."
What he is saying is as follows: The Gemara in Shabbos 113a-b writes
״ודבר דבר״ —
שלא יהא דבורך של שבת כדבורך של חול.
(Isaiah 58:13) - “And speaking idle words” - that your speech on Shabbat should not be like your speech during the week, i.e., one should not discuss his weekday affairs on Shabbat.
Tosfos and the Rosh there explain this Gemara based on Vayikra Rabbah 34 to mean that one can't engage in any idle chatter on Shabbos (as opposed to Rashi who understands that only talking about business is forbidden).
Furthermore, the Yerushalmi in Shabbos 78b says that it was only with difficulty that they permitted one to greet another person on Shabbos.
However, the Terumas Hadeshen there brings that its Mutar to talk about these things if you personally enjoy it. However, if one doesn't enjoy it and is merely talking about it because their friends enjoy it, that would be forbidden.
