Well first of all, a respirator shortage might have ensued if everyone in the US suddenly went online to buy them. Most people were buying surgical masks, which are easier to manufacture, and about 50 times cheaper than respirators. So demand for respirators was low. But if demand rocketed, there might have been a shortage.
Secondly, respirators are far less comfortable to wear on an all-day basis than surgical masks. Have you tried to wear a respirator for even a couple of hours? It gets rather claustrophobic and irritating after a few hours. So perhaps it was a calculated policy to suggest the public wear surgical masks rather than respirators, on the assumption that the public might accept surgical masks for all day use, but would not accept respirators.
Respirators are cheap; anyone can afford them. And if the gov can send out free covid tests and thousand-dollar checks, it can send out free respirators.
If there really was still some concern about supply, health officials should have quietly encouraged politicians to incentivize manufacturers to produce respirators just like they did with vaccines. Politicians could have also helped reserve a supply of respirators for health workers (IIRC, this already happened back in 2020 to some extent).
Any kind of mask can cause discomfort but health officials recommended them anyway; so, why the double standard? If comfort was really a big problem, why is the CDC now recommending respirator use, and why didn't health officials call for respirators to be made more comfortable? If someone has a high risk of death or hospitalization from poison gas, would it be appropriate to advise them to wear a water-soaked rag instead of a gas mask because health officials assume (without evidence) that every high-risk person would prefer death over comfort?
I have no comfort issues with elastomerics, but I do have to admit that some disposable respirators can be very uncomfortable, while others are only tolerable. According to a few studies I posted earlier, most seem to prefer elastomerics over disposable respirators, yet the health officials recommend only disposables. Any kind of mask (or activity such as work) can become uncomfortable after hours of use, and that's why breaks are useful.
The best explanation remains the same: respirators weren't recommended because health officials ignored the evidence of aerosol transmission.