The reason wells are hard to shut in has nothing to do with the actual turning off the tap. All wells are designed to turned off with BOPs (blow out preventers, etc). The problem is that if you shut in a well for an extended period of time, you damage the reservoir and will have to do remedial work to get it back to its production rate (if ever). This is why producers are not keen to shut down production. They have to weigh the short term cost of the current prices against the cost of future losses over the lifetime of the reservoir