I use alpha quite frequently. I have these big formulae that need differentiating/integrating (non-linear solvers, jacobian matrices, etc.) for a paper I'm looking to publish. Now, the algebra kind of gets seriously tedious and error prone. Here alpha comes to the rescue. I don't have the budget for a complete mathematica package. So, in the end I take the results and use scipy/numpy to write the code to use them in numerical computation.

So, to that end I agree here. They are absolutely wonderful tools if you know what you're applying them for. However, they can be pretty bad if you're trying to use them to cheat (just like everything else).