Who told you they dont? But because these arent "high value" items, their import is given short shrift by those who do the deals (read, our politicos and civil servants, or rather masters).
Though I will say this. In the matter of troop living conditions, some senior officers are slavish in their desire to please the auditors, and so end up giving their troops sub par conditions.
A case in point was in the 80s when Maj Gen (later Lt Gen) Hanut Singh took over a mt div in the east, he complained of poor living conditions of troops, who were forced to live in semi pukka shelters. He demanded better conditions, but was told by higher HQ, that the conditions were fine. So he mobilized divisional engineer resources, and had wood hutments built for the fwd troops, and ordered a generator installed in each dwelling. Years later, troops still remembered him as the general who brought what the army couldnt in forty years!
Conditions in MH's are also frequently poor. Some years ago, my own grandfather (a fairly senior retd officer), many years after retirement, was visiting a relation posted in Srinagar, and had gone to visit the gentlemans wife (who was unwell), in the base hospital. At some point, he went to attend the call of nature in the wards restroom, pulled the loo chain, and had the tank come down with a crash in a heap on the floor in front of him. Naturally, a bit shaken, he asked some pointed questions of the hospital commandant, and the entire bathroom was refurbished.
The nurses later came and told him, "Sir, you have done something which we couldnt do in the last three years", and asked him to also "make use of" certain other facilities which desperately needed repair!
So that is the state of affairs. Standards are low all around.