In London and probably many other places around the World Google has only fairly recently started offering public transport directions (if they offer them at all) so I'm not sure the loss is that great. There are plenty of apps available that offer this.
The people for whom this is a big issue are a fairly small proportion of the global population. Basically those in the US who live in major cities and are users of the transit system. In San Diego and New York this is a big issue and those are centres of the HN readership and probably also the tech media which might be important but the practical impact of this limitation may be limited.