Intel intended to keep their Z series motherboards to be enabled to overclock with the K series Haswell processors so that they are able to justify the sales of a more expensive motherboards using Z87 over H87 and B85 counterparts. While the non-Z series motherboards were originally intended to be kept as value for money and with no ability to overclock, motherboard manufacturers didn’t seem to show that same intention when they found a way to enable overclocking features on the supposedly ‘non overclockable’ H and B series chipsets. In any case, its good for the people, especially considering that overclocking was originally intended to get more performance boost in your desktop system.
In any case, Intel isn’t really too happy about it ever since ASROCK, followed by Gigabyte, Asus, Biostar, MSI and ECS who have enabled overclocking features on H87 and B85 chipset motherboards, fearing that majority of the buyers will not buy the much expensive motherboards with Z87 chipset. Intel intended that K series processor can only be overclocked exclusively on Z87 so that people will spend more money on it.
ASROCK was the first to introduce an overclockable non Z series motherboard, and like any domino effect, others followed. It is being said that Intel would be introducing a newer firmware or provided an ability to block overclocking via latest BIOS update.
Whether motherboard manufacturers comply with this, especially since motherboard manufacturers left no stone unturned by advertising these motherboards as overclockable with the Intel K series processors.