IR may be thinking that it's not wastage since Non-LHB Coaches have service life of 25 years but LHB coaches have service life of 35 years. When the Indian Railways Ministry has already increased fares of various things outside the IR Budget then they need to justify the spending of revenue in front of the passengers by showing things like LHB coaches. Now passengers in trains like Poorva, Shiv Ganga and Swatantrata Sainani Exps can also say while traveling in LHB that they are getting their money's worth :)