While the lay and pray strategy is VERY boring to watch the ref has the ability to stand them up if he wants and there is no rules aganist someone doing it. It might be boring for us to watch but it is usually smart for the person doing it in a sense as that is most likely the only chance they have at winning. While there is entertainment value in wathching MMA an MMA match is not the same as a WWF match. The main goal of the fight is not entertainment but to win. I REALLY hate to watch boring fights as much as the next person but sometimes thats the way it goes down. While the lay and prey person might lose in a slug fest MMA is not just boxing, while the lay and pray dude might lose in a NAGA, jiu jitsu or a judo etc competition MMA is not just any of them either and so on. That's what I love about MMA. So many possible ways to win!! You are not limited to just your boxing, grappling etc skills.
Let's not get it wrong here because I don't care for the lay and pray tactic either and not stikcing up for the people who do it but I am pointing out it is not illegal for a person to do and like I said it is usually the last or possibly the only tactic/strategy a person has at winning said fight and the ref can choose to stand them up at any time he wants to stop the person from doing it. A big job of an MMA fighter going into a fight with that kind of person is to prepare for that and try to not let that happen, just like he would prepare if he was going into a fight with a better grappler, boxer etc....