I can only say two things about this, @TheMosby. No, three actually. First, what @Bananabelle96 describes is pretty much what I hear from students at all top research schools when it comes to math departments. So this seems to be reasonably common for whatever reason. Although I will say that my D’s housemate her last 3 semesters was a math major and he really enjoyed most of the profs, but perhaps he also was able to understand the material more on his own, I don’t know. He struck me as quite the bright sort.
Second, and she doesn’t mention this but again I hear this about every school almost, is that a lot of the profs and grad students are hard to understand. I have heard that about a couple of the profs at Tulane math, and I think that actually might be more at the root of what you are hearing. It is a tough issue for all schools because most of the top talent seems to be foreign born, and losing their accent isn’t a real priority for most of these people, whose very job means thinking more than talking. It is easy to sit here and say “Well, they should all try harder because they have to teach” but when you look at the entire context that at first they have to prioritize getting their Ph.D. (which while most often is done in this country, it isn’t always). Then they have to focus on getting tenure, which means publishing. So while I don’t want to dwell on this, my point is I don’t think Tulane is any different than HYPS, Chicago, Duke, Vandy, etc. in this regard. I know the complaints from the west coast schools are deafening sometimes. This is what I hear, anyway. There was a little of this when I was in school, but far far less.
Third, I have to say the chairman of the department has always seemed responsive and accommodating to undergrads, and a nice person. Not sure how much that helps, but it is something to consider.
I can’t remember if you said you have already been to Tulane or are planning on going, but if you are going to be there don’t be shy about trying to meet with a couple of the profs, maybe even have lunch. And if that were to happen, don’t be afraid to raise some of these issues, in a diplomatic way of course. Because my contention when it comes to almost any major at the undergrad level is that most schools will have extremely competent instruction and plentiful course options so that the student is as well prepared academically coming out of one school as another, at least within the top 100 or so schools on the USNWR list. After all, differential equations is pretty much differential equations, and it is not unlikely that you would use the same book at Harvard or Yale or Stanford as at Tulane. You get the idea. I think the real differences lie elsewhere, and depend on how you and the school fit each other overall.