I do agree it can get annoying when you get teleported out of nowhere. Sometimes you just want to log on quickly; maybe to just check something or have some sporadic IC roleplay. And suddenly, you're forced to be moved into class and then stuck for the next two hours. We've all been there during our first days as students, and we get how upsetting that can be in these specific cases.
That said, it's important to remember that student attendance is one of the core principles that keeps the school faction active and kicking. If staff stopped enforcing it, class attendance would drop significantly, and the faction as a whole would suffer (considering SchoolRP's main roleplay focus, this wouldn't be ideal). We're not denying that unlucky timing can be inconvenient, but this system exists to keep and maintain the core focus of the server.
Besides, you can always find new roleplay possibilities inside school! With all the plugins and roleplay infrastructure SRP has developed over the past years, you'll surely find something to do while you wait ^^
