> if you distribute something with GPL code, you must make the source available to anyone that requests it

That's only true if you're operating under section 3(b) of the GPLv2: explicitly offering source via mail order. If you offer GPLv2 source via mail order, you have to honor mail order requests from anyone. However, you aren't required to offer the source via mail order at all, as per section 3.

In the GPLv3, the analogous section, 6(b), is actually further constrained: if you explicitly offer GPLv3 source via mail order, you're only obliged to honor requests from people that have the object code in their possession.