This has nothing to do with your preferences. This is network management pure and simple. This is how you implement efficient infrastructure in congested locations like stadiums, airports, and large retail (where you may have no signal at all). Whether the cellular radio or wifi radio is used has nothing to do with you; you are paying for a connection and there are some very intelligent people tasked with figuring out the best way to solve that problem. Because if they didn't, your phone wouldn't have connectivity in those locations and you'd be on here complaining that their service sucks