Why PAS Can NEVER Be Sharing the Same Bed With UMNO ?

These are entirely personal observations and deductions based on my informal interactions and discourses with some UMNO members I happen to meet and be acquainted with. The observations I have made may not necessarily reflect the actual traits of UMNO members in general but they nonetheless could form some basis for judgement.
It basically goes down to divergent sets of value systems adhered to by the opposing parties. One firmly believes that in order to raise the economic status of the Malays, they must be granted licences to operate casinos while the other considers it absolutely "haram" (strictly forbidden); it is okay to invest in pig-rearing, brewery, and casino projects to derive economic benefits for the Malays, which the other party considers them abhorrent. It is okay for them to imbibe alcoholic drinks while the other detest them. They say they can use interests (usury) from their saving deposits for the purpose of performing the Hajj when the other opposes such edict. Their dress codes are distinctly different from each other. Yes, all of them perform the solat (prayers), observe the fast, pay zakat (tithes), perform the Hajj but that's where their similitudes end. Though they both believe in Allah, one of them simply rejects the Syari'ah Law dismissing it as inappropriate for a multi-racial country like Malaysia.
Given the stark differences in value systems of PAS and UMNO, certainly they make very strange bedfellows.