This is part of the changes with the latest patch and skill injectors. That means, anyone in null with a jump clone can jump to highsec, (or daytrip as a wh pilot) plug in whatever skillbooks they may want, and head home to train as they want.
There should not be any need to pay over the odds for skillbooks in null, nor be unable to train that next desired skill in a wormhole. Of course, this requires forethought. As such ... next trip to null, I will restock skillbooks.
I have another thought and there may be a time I would be tempted to use skill injectors (but still not any extractors). That is on those horrible skills where, in the middle of one remap, you need to swap to a different one.
An example is tactical logistics reconfiguration.
You have dreams of being a repair pilot in a capital ship (previously a triage carrier, soon to be a force auxiliary pilot)
You have been training Long Range Targeting 5 and Signature Analysis 5, both are int/mem skills.
Next you need to train what is now called Logistics Cruisers 5, which is a willpower/perception train. Then .. you go back to Int mem to pick up Tactical Logistics Reconfiguration, which you really want at 5. After just a few more int/mem skills (Capital emissions and remote capital armor/shield) you will most likely want to swap back to Per/Willpower for your new hull.
Now this swap back and forwards is painful to anyone trying to optimise attributes. Plenty of capital pilots before me have done it, and more will continue to do so.
Even a new capital pilot will suffer from diminishing returns, and I certainly know that mine also have subcap skills so will experience them even more. The temptation will be there if I go through this on another pilot.
Skill injectors have been railed against, but the prices and trading say that someone is buying them.