Yes, it is unreasonable to ask and/or expect students to do 1-2 hours of reading work prior to coming to the first class of the semester. It’s not just that, as others point out, your expectations will surely not be met, but, equally importantly, that such a request is unfair to the students.
What’s reasonable is to expect the students to come to the first class knowing the officially advertised prerequisite material. Requiring more knowledge than that is effectively moving the goalposts, a kind of false advertising, and a (mild) abuse of your authority. In addition to most of the students ignoring your request, even the ones who do the reading may still resent you for this misrepresentation, and for trying to monopolize a part of their time that is not yours to monopolize - the time before the beginning of the class, when students may well be busy with other things they had planned to do.
At the end of the day, it’s worth remembering that it is your job to teach the material, and that the time between the start of the class and the end of the semester is precisely the time scheduled by the university for the students to learn that material. Assigning independent reading, while certainly acceptable, is something that should be done sparingly, and not before this official time period. Your intentions seem good and I sympathize with the general idea: I may also wish that if I’m teaching, say, a complex analysis class then students should read at home the basics of contour integration before the course starts so that I can cover more advanced material. But that’s my problem, not the students’.