Borna Coric is another ATP player that also stretches and warm up for 60 minutes before picking up the tennis racquet. Saw him did that in person at AO. He is baby Djokovic when he plays his best and baby Murray when he plays at his worst. Dude is the beast in person.Well, that's one example. Is there another example? Also, the data is conflicting at this point as far as I can tell. It could very well be that some people benefit and some don't, so trust your own judgement on it. Just go into it with open eyes and don't be dogmatic if there are signs in the other direction. If you're going to do that much stretching it may be better to do it after the workout. You can probably google a bit and find some actual studies on it if you're interested.
Having said that, I do see your point. It might not work for everyone. The medical community is split on this as well.