I was with you until midway. You're making quite an assumption while the NTSB's investigation is still ongoing. We don't know the root cause - Those bolts may have very well been in place and passed an inspection during install, but rattled loose and fell out (and then subsequently were blown out of the plane when the plug failed.)
United reported loose bolts, not missing bolts. This indicates a more systemic issue and not just a miss by an Alaska Airlines maintenance worker taking a phone call. If the systems involved in the failure are all "Boeing", it doesn't seem unreasonable to consider changes, such as requiring a 3rd party with no self-interest in rubber-stamping the go-ahead, to inspect the work.