Remove Shatter and Secure from the rotation.

[Valence]

This also leaves your own primary outpost vulnerable to being captured.
That’s the main reason it now provides an occupation damage buff and is positioned farther from the spawn point.
The 15-second invulnerability on respawn has become largely irrelevant, as it typically expires by the time players reach the main outpost.
If your team is aligned with Horde Stompede, you’ll often see a single enemy player repeatedly capturing main outpost—forcing your entire alliance to scramble between the outer node and main outpost.
This kind of distraction can significantly impact your team's overall score.

Perhaps this is what the design intent was, but in reality it doesn't work because of the horde stampede that you mentioned above. There is always people respawning, and unless you want to get bogged down into fighting them one by one as they drip down and draw more and more of them to you, you need serious numbers (light party or above) to seize that outpost and hold it. And then their blob inevitably lands onto your face precisely because even if they're middle, they can just teleport back with the teleporters, or if someone actually smart in their team tells them in chat, they can also just /return and smash you to smitherens, or pincer you between the people coming back and the people respawning or porting back.

In most games when I see an enemy outpost getting captured is when one of the teams/blobs has had free leeway to push all the way to said base without being contested, or being contested by one or two single lone souls that just get into the zerg meatgrinder. Fact of the matter is, they did everything to favor blobs since they increased mount speed in ShB, and doubled down on it after by adding fast movements tools like those new allagan teleporters to make sure people don't miss the action. Guess what happens when you can't miss the action? Just follow the blob.

There is also another thing that tends to feed into this incentive as well, since the map design and mount speeds are just big enablers, and it's that most of the casual pvp base thinks in pve terms (which is very notable in CC questions from newbies: "what is my rotation?" "what is my opener?" "do I keep the GCD rolling?" or when you just see the DNC partnering a BLM). Thinking in pve terms, they just imitate what they know, which is following the blob like in hunt or fate trains for example, or exploratory content. It's what people tend to do in MMOs, and SE is just enabling it.

The thing is, you could already steal the main outpost before with small teams as well while everybody was mid. In fact, it was easier, precisely because the only way to go back in a scramble was through /return, because no teleporters otherwise. Or just jumping down the cliff, which also works well tbh.