Parsons,
there's so much that cannot be determined from your post for anyone to make a judgement call.
perhaps there was a cross wind, perhaps there was more traffic on the taxi ways etc etc blah blah..
the fact is, your instruction program will be modified to fit how you learn and your individual capabilities...
as a point you may have observed others doing it, but that doesn't mean you know how to do it.
flying straight and level is a base for your flying skills that you will develop; you may think that you can handle the whole flight but you cannot and will pick up bad habits that inhibit your learning later on.
sorry, but the fact is, you dont know it all, you are there to learn.
as a side story back when i did my PPL there was another student that was a 'know it all' backchatted the instuctors, told them they were doing it wrong and wouldnt overcome his bad habits. none of the instructors liked teaching him or flying with him. consequently he solo-ed a lot later than i did, passed his x-country a lot later than i did and also his PPL.
the difference was that i sat down shut-up and listened, learned, asked questions no matter how dumb they seemed and if i didnt feel comfortable with something said so and why. you need to be part of the learning process and that means learning, even if you may feel that it is beneath you.
disrespected by your instructor? you seem to be making a fair job of that yourself.