So please stop projecting your paranoia onto me, you can keep your tinfoil hats I really don't want one.
I'm not saying that no one wanted these ideas but I'm willing to bet if you were to look through the official forums as well as those of fan sites the desire for cross realm heirlooms would far out weigh those for guild transfers, a revamped old world or, even, Pandaria.
I would imagine that developing a cross realm heirloom system is much less work than an expansion so why are they unable to provide, us, the players with something most of us want?
You are dismissing information that does not agree with your argument and using false assumptions as a basis for it. The anecdotal evidence you provided is near useless due to it being a miniscule sample size. You are assuming the majority of players do visit and post on the forums, that is false. You are assuming that the majority agrees with you on wanting the ability to mail heirlooms cross servers, you do not have the information necessary to make such a statement with certitude or have not provided such information if you do possess it.
As I have stated multiple times I believe they have other projects to work on that are much higher priority due to them having higher relevance to a larger number of people and do not wish to detract from those projects for such a minor feature. I am stating my opinion and saying it is such, I am not trying to masquerade an opinion as fact.
Whilst the majority of players do not visit the forums the topic of cross realm heirlooms is raised enough to assume that this a something the player base would want, it would seem that more people want to send their heirlooms to alts for free than those that want to pay for a guild transfer.
Of course they have projects that are of a higher priority than sending heirlooms cross realm, a cross realm heirloom feature would impact on the profits from those that character transfer to send heirlooms to their alts. Whilst there are people who are not only willing to pay for this service but to defend it they would be idiots implement a free way to transfer heirloom from realm to realm.