I've yet to hear a proposal for how you'd "disallow" it. Mostly it just sounds like you want to tell people how they can and can't transact and are playing the hysteria card to make it sound as though people should agree with you. I see your cries falling on deaf ears. People are going to continue doing whatever the hell they want. Because they can.
You bid for space in blocks. That's the design. Always has been. Sometimes it gets expensive. That's how bidding works. The way Bitcoin was intended is that no one can interfere with anyone else's transactions. That's what it's currently doing while it continues to resist forum hysteria about it supposedly being "slow" and "expensive". Bitcoin is doing exactly what it's supposed to do.
If you want fast and cheap, find a design that wasn't based on bidding for finite space in blocks. You'll soon learn what you're sacrificing to obtain fast and cheap, though.