The interceptors example is just an extreme circumstance to make an example, it probably won't realistically happen in that form, but the potential for it is there.
Here's the thing right, no matter the system quality, there will always be groups who want to take your sov just for the kicks. Sure you have to settle for a shitty system, but that doesn't mean you'll be able to hold it or that no one will come and try to take it. As a small alliance you will get fucked by any entity who knows what their doing, and they only have to risk a few ships to kick you out.
Currently if an entity like PL or NCdot wants to take sov, or fuck with sov, they must move a large amount of capitals and super caps. put down staging towers, fuel these staging towers, move SBUs and TCUs, then put the SBUs at risk before the timer are even created, organize fleets a week in advance, etc. It's tedious work that no one wants to do, and is the major reason as to why their isn't a huge war going.
With the changes, all you need to take sov from a small alliance is a single subcap fleet, the come through, RF the system, leave, come back the next day are your sov is gone.
There is no serious effort needed to be put in by a large alliance to take sov from a smaller alliance, and they will kick you out and destroy your sand castles just because they can.
From older players point of view, it doesn't sound fun having to log in every night to ward off some roaming gang who decide to RF your systems. They only have to spend maybe an hour in your space to put it at risk and they don't even need to form up to force you to log in as another roaming gang might come through the next time and take your sov. Not everyone wants to, or can play eve every single night.
The real winners with this sov change are huge groups like goons who can afford to send 500 people to other side of the galaxy while still having their home perfectly defended. Everyone else loses.
Also, a -0.1 system is so awful that it wouldn't support a small alliance, maybe a single corporation.