Software is completely dependant on the type of teacher you get. A lot of software teaches are absolute horseshit and you end up self learning the course if you wish to do well in it (that is, if don't get completely demotivated towards the subject and end up not studying at all - thankfully I'm able to drop it next year.) If you wish to pursue software, make sure you get a copy of the Sam Davis textbook if your school doesn't already supply it. Our teacher gave us a book from 2001 based on the old syllabus, and I ended up persuading him to purchase a load of the Davis textbooks + a teachers copy (rip school budget).
Whereas business studies is somewhat useful yet dry and boils down to regurgitating the textbook in tests. Critical thinking is certainly lower than that in software, however you will almost always have a good teacher. It is also an essay heavy subject, so if your good at those, you should already be leaning towards it.
Basically comes down to whether you are willing to self learn software or not (unless there is a decent teacher) and whether you have a passion for the subject (ie programming or computers). If not, for the sake of your atar and mental health, go with business lol.