Constructing this as some sort of malicious action of foundries is quite far from the truth, though.
In the fairy land of foundries, there's the great and unrivaled king – Monotype – and then there's a thousand princelings with a few princes (Adobe, FontFont) sparkled in between.
Type is a TINY market. In a back of the envelope calculation last year, I found that the whole type industry is generating around $120m – $150m in sales every year. Monotype/Linotype is around $50m of that pie already. Adobe Type is another $20m is I recall correctly. FontFont is a private company but I take their overall revenue is something like $10m.
Most other foundries are 2 men operations that produce a small profit but not enough to make huge technological investments like hand-hinting the complete back catalog.
At that point a foundry has three options:
1) Not offer their catalog for web- and app licensing at all. The respected resellers / foundry VLLG (Village, http://vllg.com) does this currently, for example.
2) Offer them on request, with the possibility of having a conversation with the customer about their expectations and what they're really getting for their money. See the note in the sidebar on http://commercialtype.com/typefaces/atlas as an example for this.
3) Offer them no matter what rendering quality on Windows devices they can achieve.
While horrible Windows rendering this does not apply to mobile app licensing due to better rendering engines and high-resolution displays on most current devices, it's still a large effort for most small foundries. Setting up the products in the e-commerce backend is the smallest part of that. And all that effort is a bet on (currently) a very small possible return.
And last but not least, one thing to understand is that most foundries make a huge percentage (60%+) of their money licensing large volumes to bigger companies. One corporate design may include office fonts for 500 workstations. While I personally love selling to small studios and startups that love our work, it's not what pays the bills.