Isn't there a simple way to script tests of a website?

We build sites using ruby/rails and we have thousands of simple test cases: log in with this user/pass click this button enter this sku click that button the page should say "$2.59" Success or no?

I can't understand for the life of me why this is such a complicated thing to make into an automated test. Our qa team says that Selenium is "not scalable" and that coding rspec "integration" tests takes far too much time.

To me, it doesn't need to be in rails. It could just be something that runs locally on a desktop? Although it could get up to 400-1000 page renders.

Are there simple tools for doing this? Why is this so difficult/complicated?