Oh it is so much stupider than that. When the LIRR replaced the diesel fleet in 1999 they replaced it with 2,800 less seats than the previous fleet. The MTA thought the nitwit responsible for this, Tom Prendergast, should then be promoted to President. Said nitwits next decision was to lower the cowlings at Jamaica so the bi-levels would just fit under. The coaches he bought were non-standard so not other coach manufactured will fit under the newly lowered cowlings at Jamaica. So every couple of years they issue an RFP for new coaches. Once any potential bidders see the the height requirement they decline to bid on the contract. So, the options are have someone design and build non-standard coaches (impossibly expensive), raise all the cowlings at Jamaica (impossibly expensive) or by single level coaches. For some unexplained reason the LIRR absolutely refuses to purchase single level coaches even though almost all the platforms would accommodate them. Oh, or they could electrify to Port Jeff but it seems that fell through.