I'll give you a protip; there are more casual players out there than hardcore players. If you check all successful AAA titles, there are more content for casual players than HCG there. Just deal with it. XI era is over, no one is willing to camp a stupid NM for 3h, and then to lose the claim against a LS botting...
And even if you get the claim, then you need to drop the item you want (or even try and kill the nm properly without getting MPK'd by a competing LS).
Competition is fine, but shouldn't be frontal like that and rather be in instances/raids.
Make raids that are so hard that only HCG will be able to fully clear them within a month, while casual may need to wait the next patch in order to clear it. That's how content have to be designed. I agree with the fact that a HCG should be rewarded more than a casual player, but frontal competition in a PvE environment is just pointless and lead to what we all know. Use of third party tools/cheats, griefing, etc.
I remember firsts Rift raids/T2 dungeons being so hard that casuals couldn't simply clear them and PUG would just fail everything. It took several patches and nerf for an average player to be able to access certain piece of gear. On my shards for example, we were only THREE guilds being able to clear latest content, and we were competing for shard's first. We all had a sense of competition "Oh Guild XXXX managed to beat Boss XXX yesterday! Damn we're late, we need to try and get that and the next boss down before they do..." etc.
So people still compete, HCG gets way superior loots than casuals. No frontal attacks, no grief, no insults/drama while people camp, no use of tools to get a direct advantage over others.