A question about tubes for manufacturers

Have a question – why can’t the medicine tube and toothpaste tube manufacturers put fold over tabs on the bottom of the tubes to keep them folded up? I wrote to Colgate 10 years ago and they said their engineers designed a tube that did that and sent me a 50 cent coupon for toothpaste. These tubes just don’t stay folded up; you need to use tube rollers, paper clips, rubber bands, etc., to get the job done – just asking.

Beverly D. Walters