Personally I'm fine with Luton being there - they earned it. Whether they spend loads of money trying to stay there or not, or try and change their style of play or not, doesn't bother me one bit.
They need a new stadium and focusing their PL windfall on that is a far more sensible approach than spending loads on players who probably wouldn't keep them up anyway and would just waltz off after a year with a huge amount of that money stuffed in their back pocket. In fact, there's part of me that would love them to stay up having spent next to nothing and playing the type of football they're comfortable with. Show up the billionnaires spending ridiculous amounts of money on transfers and wages. If they try and play PL teams at silky football, they're going to get hammered. So why not try and do it the way that's served them so well over the past few years? You wouldn't look at a small boxer and complain that they didn't stand toe to toe with the heavyweight champ and slug it out.