It must be a Malaysian thing. You will notice the first question prospective buyers will ask is how many bedrooms. They just want more bedrooms. 
Property developers want to make the price affordable. With the current per sq ft price being what it is they reduce the overall size. And since people like more bedrooms they squeeze in one more than necessary.
In my discussions on residential properties, with family and friends, I have always said that there is plenty of land in Malaysia. All residential properties should be at least 1.5 times the present size. That would be comfortable living. 
Note:
1) Property prices only sky-rocketed from late 2009/early 2010.
2) The RM started its slippery slide downwards from April 2015.
" In the land of the blind the one-eyed-jack is king."