I'd say any good player beating up a weaker player is rather comparable.
It's just the systems and the design of the game don't encourage it as much.
i think you'd actually have to see this setup.
good players don't go in and beat that setup. they get chewed up like everyone else.
there's also an aspect i didn't mention that there was evidence they were forcing host migrations any time someone got to the banshees before they did (getting the banshee was the first key to map control) but that's really beside the point. the point is that bungie/343 are prone to designing maps that are painfully unbalanced in ways fighting games aren't. like you're never going to spawn into a fighting game mid-match to find yourself in a 100% no-hope locked down spawn camp situation.
fwiw my thoughts on those halo situations is that it's the nature of the beast and you just hide & walk away until the game is over or disconnect (usually the former given that halo actually has disconnect penalties). no one has any obligation not to maximize advantage to get kills.
playing for maximum advantage doesn't equal griefing (using host migration to reset a situation to create spawn traps is over the line, though).