You state that the film 'seems to miss the opportunity to accurately portray the conditions' yet even in the 34 Division sector (La Boiselle -which included the once fiercely contested Glory Hole) the grass was high and green on 1 July and the effects of war were deceptively masked. I only know one sector of the 18 mile Somme battlefield truly intimately but I do know it was never 'a moonscape of mud' on 1 July 1916. Parts had seen much scrapping but for the most partit was more scratched than scarred. Indeed if you study the attack made by the reserve Brigades of 34 Division you will soon see that they came under sustained machine gun fire long before they encountered even the British support trenches. Ternan's Book on the Tyneside Scottish contains photographs bearing this out.
I can understand a yearning for what you consider to be accurate mise en scene but given your am consequently bewildered by your revulsion towards to the portrayal of swearing in the trenches. I was privileged to know Reg Glen of the Sheffield Pals and a handful of veterans from the Tyneside Scottish and Irish. Their command of invective was something to behold and I somehow do not think they were exceptional in this regard. The language used in the film was mild in comparison.
All told, you either seek accuracy or you don't. You can't have it both ways