Parametric, on the whole, simply compensates for the inability of the user to adequately visualise their project until they have it laid out in front of them.
It's no bad thing but not everyone needs it, if you're designing a Power Station you NEED parametric, if you're designing a house, a clock or even a moderately sized multi-cylinder IC engine and you need parametric then you may be unable to visualise your project adequately and may achieve good results but might easily miss out on an outstanding result because you don't truly understand the minutiae of what you're fiddling with.
It's the plague of our time that everyone with a PC thinks they are a Publisher, an Engineer or a Designer and very few of us are.

- Nick