Ah this discussion, brings back memories 
I’ve been through all the technological DJ transitions: started out with vinyl (there was nothing else, and I know now it’s romantised but essentially all us DJ’s back then were complaining about crappy needles, resonating sound, skipping tracks, heavy lifting etc.). Then the Denon and Numark CD 19” rack units started happening, with little pitch sliders and separate control units, and we started adding CDs to the mix. Then the first square Pioneer CD unit with the small black jogwheel, wow, that was something! We started bringing wallets with burned CD-R-’s. Pioneer started dominating the clubs with their CDJ’s. Also, Final Scratch happened, and DVS became a thing, and Traktor and Serato where ruling the DJ software.
I’ve been using all of it, and always people start dissing you that this is “not real DJ’ing” or “not professional”. Typically, these complainers are other DJ’s, because if you’re a real professional DJ, you know how to make a crowd move, and people don’t care, or have time, to look at your screens or devices. Only trainspotters, standing in corners and not dancing care about the medium LOL.
I am now transitioning from Traktor to Djay Pro, because I feel Djay Pro has the brightest future, and has the best technical implementation and foundation of all the DJ software right now. UX wise it can improve, especially in the library department, but I see a very high velocity of development and improvements, which I really love and makes me remember the old days of Traktor.
So, to answer the question: you decide what is professional and what is not. And if you’re a good DJ, you simply can use ANY tool to make the crowd dance, because in the end it’s all about the cook and not the kitchen.