Ciencia Al Poder wrote:
If it wasn't added due to performance concerns, what makes you think it will be added on wikia, which seems to be also concerned on performance as well? I don't think that's going to progress in any way...
Well, global lua modules weren't added to WMF's scribunto partly due to performance issues related to the so called scary transclusion. Yet they were overcome by wikia using a somewhat different infrastructure. A considerable number of performance problems can be overcome either with software or hardware.
As far as the query API is concerned, some of those queries can actually be exposed in a different way and cached indefinitely. Special:Prefixindex for example is known to be far more performant than the equivalent API query[1] . The problem is that with lua you could potentially use loops multiple times and affect the performance anyway. Although that can be overcome by maybe only allowing one use per page and limiting the no of rows returned, or some other approach the WMF or Wikia engineers can think up.
Performance is not the only reason some of these ideas are not rejected. The fact is that much like wikia (or any company / institution), they also have other priorities.