Considering this game's based on MMO structures without actually being an MMO? Yes. It's an opinion. And a common one in gaming. If they don't do this, then there's no point to new content without eternally making more and more broken weapons/armor until the point that the Y1 stuff would be useless to begin with. Horizontal progression's a wetdream, and the sole 'successful' case (Final Fantasy XI) has most of it's members noting that they saw it as good then, but then realized after quitting that it doesn't work (see trope: Rose colored glasses). Because either A: you're getting more and more hyper-specific equipment to handle individual situations (meaning in case you're blind to it, enjoy grinding countless hours to get that legendary raid chestpiece with all the exact skills/upgrades you need to fulfill your roll in ONE SPECIFIC FIGHT IN A RAID OR END UP KICKED), or B: you're seeing them releasing more and more overpowered equipment and phasing out the old equipment anyhow (IE: imagine if instead of the simulant we got a new rocket launcher that fires 3 rockets at once without using more than 1 ammo. Your Gjallahorn's useless now, as it does less than this 5-rocket firing monstrosity anyhow). Diagonal/vertical progression is the standard for any game that's expected to last a long time. Since it seems we'll keep our stuff into year 3, 4, and beyond, then it's inevitable that the stuff we have has to become obsolete eventually or else there's no reason for them to produce more stuff - they already produced the most OP weapons of each category (except Fusion rifles, let's be honest folks they suck D:).

Losing a whole year's worth of effort is something I'm fine with because I want to see and use new equipment, try new perk combinations, etc. If I was still using VoC / Fatebringer / WoC, Black Hammer / Found Verdict, and Gjallarhorn, I'd already be getting bored. So I'm good with that. I haven't tried the new raid yet, but I'm pleased that it's longer than VoG and especially Crota. I agree with you about private matches - that's definitely something I was wanting to see.

I take it you don't golf much

This ^