They probably aren't as bad as people are making out, no, however I have seen a few cars with Rotas on them, and for anyone who knows anything about cars you can tell they are an imitation wheel. Park a car with rota gravels next to a car with sti enkeis and you can easily see the difference in quality and fitment. Of course if all you care about is impressing people who know nothing about cars, it's fine, but isn't your car about you?
If you're the kind of person that buys imitation iphones from China then rotas are for you. It's like buying a Chrysler 300C. Everyone knows you bought it because you wish you could afford a Bentley.
However, for the P platers I can understand why you wouldn't think it's worth it to put expensive wheels on your car, but the smarter thing to do would be to save your money alltogether and wait until later in life when you have a car that IS worth buying the best parts for

Believe me there is no need to rush things in life, I drove around in a civic hybrid for 3 years while on my p's and was the butt of all my friends jokes before getting my current car, and had enough money saved to do all the mods I wanted to do!