The whole point of requiring everyone to get insurance is so that you don't have just the sickliest and oldest people getting insurance. Insurance is meant to spread the risk amongst everyone who pays premiums.

Additionally, not having insurance for primary and non-emergency care will make it much less likely that people will even end up in the emergency room. (No checkups, no outpatient)

Even worse, having emergency room coverage only encourages people to use the emergency room more often than they should.

Though I wouldn't expect our last president to have much of a handle on economics and business, considering his track record. Either that, or he was purposely trying to destroy the program (he was, but it was probably both reasons).