I really don’t know how a “reader” can see that the rishonim didn’t have a mesorah, because I’m not a reader; i am a lomeid, and that means approaching the rishonim not as a book but as a piece of torah that is part of the continuum of Torah. You’re suggesting that i “can’t put my finger on it” simply because you cannot put a finger on what i was talking about.
I’ll be clearer – there is a mesorah in how to understand both the language of chazal, the words of the rishonim, and how to properly use Talmudic logic to understand both. This is why steinsaltz, who had no formal education, is so off base with his pshatim (see rav aharon Feldman’s critique for examples). What would make sense to “echad min hashuk” isn’t always a good sevara or shmaataa aliba dihilchasa.
The mechanics behind a gemara, which we call lomdus, is entirely mesorah driven. It’s hinted to in some rishonim, including notably the tosfos ri”d, called in yeshivos “reb chaim of the rishonim”, but mostly was not comitted to print. Rav Boruch ber (cited in rav hadomeh lemalaach) said that when writing chidushim, one should not write “too much”, not the entire shtikel, because we’re not writing artscroll type books. There’s a mesorah for the difference between a rashi writing “begemara mefaresh” and “mefaresh begemara”, as quoted in the shem hagedolim from the chid”a (could have been a different sefardi sefer, I don’t remember the name very clearly, just that it was sefardi)
Chidushim are rooted in that passed down tradition; they’re not a free for all. If someone wishes to open a gemara and pasken halacha without rishonim and achronim, he is rightly deemed a baal gaavah and is held responsible for allowing that which is assur. For example, the academic mentality would not see anything wrong with annuling yom tov sheni, chumra derebe zeira, or other issues that one can dismiss with simplistic kashos. Yet one who does these things is in violation of halacha, because we have a mesorah that we do not deviate from.
Bombarding with questions doesn’t dismantle an argument, but it is a debate technique used to make the other side less appealing, since it raises more questions than it answers; it’s not a real conversation point though, and it’s also evasive, like putting up flares in the hopes of confusing an attacker.
It doesn’t mean that every perush of a given gemara was passed down, much like the discussions in the gemara weren’t passed down, but rather the product of torah reasoning that is based on the amoraim’s rebbeim. The methodology of seeing a good sevara from a bad one is part of this mesorah. You’ll notice that rishonim often say pshatim that are initially hard to understand, and could be dismissed by superficial kashas… only for someone like the chasam sofer or reb akiva eiger to come and completely overturn the sugya and show how the rishon was the best pshat.
I wonder if you’ve ever learned in an iyun driven litvishe yeshiva, or if your experience was in a certain element in YU, an academic setting, a chasidishe yeshiva from which you weren’t intellectually satisfied, or a halacha kollel… it’s easy to hide behind the veneer of achievement in having completed many mesechtos, perhaps even shas (i admit i have not made a siyum hashas), and feeling that one has a complete grasp of gemara…enough to dismiss elementary teachings that one receives in a middle school setting. People who relish discussing “themes” in rishonim are usually at a loss for prime examples if asked; rishonim are way bigger than us and we should endeavor to understand what we can of their words without fooling ourselves into thinking that we can understand overarching “up teitches” the way one would with Dostoyevsky and Shakespeare.