Before my earlier post gets lost for reference I think I should revise. There is definitely the emphasis on bittul and not priding oneself for ones wealth or even spiritual standing (you would see that expressed practically with the lack of kovod people attribute for themselves and the lack of classes with the rich or not, everyone mixes without airs, for the most part) but I guess the rich / poor thing neville was saying isn’t the reason for current lubavitch dress as all the other Rebbeim wore streimlach or the like and only our Rebbe dressed differently the reasons for which were brought earlier in the thread. We just go after our Rebbe.
As far as the tie thing to me it makes perfect sense but that’s for another post.
Sechel youre addressing from your perspective and circles and I’m addressing from the discussions I’ve heard between my father and brothers who were in Yeshiva and my husband and brother in law who is a shliach in Yeshiva… There is that way of thinking or all bochurim would just tuck in. It is a topic of conversation and discussion among lubavitchers and its silly to make it sound as if everyone tucks in because you do, when that’s not the case. There are different approaches in different yeshivos as well. My brother is in a Yeshiva where the married Mashpia doesn’t tuck in apparently (and its mainstream, not detroit and not Queens etc) although that is rare. Some of my other brothers have attended another Yeshiva where the bochurim would get a knas for an untucked shirt