I see this has come up a lot in the community already, so I won't bore you with the details as to why this feels necessary for a wary freelancer parting with their proposal credits.
The reason, from what I've read back on 2016 posts as to why the buyer's profile view has been removed at proposal stage is that they may be contacted directly outside of PPH. Or even bombarded with requests for work.
I don't see why this would happen if the buyer, like a freelancer, doesn't or isn't allowed to disclose their contact details, company name etc in their profile and their profiles are moderated just like freelancers' for this information.
I understand there's going to be buyers who haven't used the site before and want one off projects done. As it stands though I'm very reluctant to make proposals to buyers with 0% projects awarded without some background information about them.
Essentially, freelancers would be more inclined to part with their proposal credits by gauging whether they buyer feels trustworthy.