I think this is the real issue. Sideshow does not cost less. They have actually been more when you compare what a figure comes with between a Sideshow figure and a HT one. The X-Wing Lukes were both crazy expensive for them to have been bare bones. The SS Jedi Luke is the only "reasonably priced" figure in a while but that's probably only so they could compete with the HT version, and they're probably selling it at a loss! It used to be that SS figures were a good amount less, and that was a good niche for them to be in. They were of a slightly inferior quality than HT, but since they cost less, it was worth it to tolerate the issues a SS figure would have. Now that they're both roughly the same price, and with SS even being more expensive, it's an obvious choice to go with HT, which has a better product AND costs less! Like many have said here, it would be in SS's best interest to focus on aliens and robots that HT wouldn't get around to doing. SShas proven they can do them well, and they would have no competition from HT.
I will say that I would have no desire for a HT Scoutie since I'm pretty happy with the Sideshow version. The (minor to me) problems it has don't bother me and it wouldn't be worth the trouble to upgrade.