cherrybim-
I’m not sure what you meant.
‘Some consider it a chumra’ is not the same as ‘some are machmir.’ Being machmir means being stringent, and the term is not just used for ‘chumras’ per se, but for keeping any stringent position in halacha as opposed to a more lenient one. That’s just the nomenclature.
Thus, when I said some are machmir because of that I meant some hold l’halacha that it’s assur for that reason, not just a chumra. I am not noheig that way, but you asked Trying my best why one would differentiate between c.s. and other areas of kashrus, and I was merely clarifying the approach he/she* brought up.
*Sorry, I really can never figure out the gender of each person here – perhaps someone should suggest to the mods that next to each user name there should be an ‘m’ or an ‘f’.