have they said why not?
Things will be different with it changing to becoming a persistent world "full" mmo but keeping henchues is better, IMO, than making content soloable. Then it takes away the need to group if you can solo everything, henchies take away the needto group as well but it is still group content so a lot of people will still group over using henchies.
Strange decision to my mind, is there any stuff talking about the reasoningbehind the decision or was it a case of "it will be so" commandment with no explanation?
In GW2 you can still group up, or not group up. The content around you will scale in difficulty to the number of people around.
Some content wont be soloable like Dynamic Events and big bosses, but the explorable world and personal story line which are most of the game will bo soloable.
Dynamic Events also dont require you to actually form groups - the idea is that everyone and anyone can join them, so people will turn up regardless. For organised grouping there will be dungeons with a 5 player party size, down from 8 in GW1, but if you've played GW1 for a while you will know that this is a good idea - You an almost never make a full group of 8 in GW1, and finding healers is almost impossible, hence why people use heroes and hench. Also heroes and hench were incredibly more capable than the average pug group, which led to loads of people abandoning grouping altogether because most pugs in GW1 literally sucked and were a terrible playing experience (Join a pug in GW, chances are you will lose. Join a pug in DDO, chances are you will win easily, even though a lot of the content is harder).
The main problem with GW1 was far too many skills, giving players complete freedom over their skill choices, and the majority of the skills being incredibly weak and imbalanced. In most balanced RPGs, you can build your characters in almost any way and they can still be very capable. In GW you needed to run specific meta builds or at the least be better than the henchmen ... That sounds easy but it is incredibly unbelievable how many people would simply load up the most abysmal skill bar imaginable, plus if you tried to help them by giving them a skill bar, the chances were that they would suck at playing it.
GW2 will be a lot different to that with 5 of your skills being determined by your weapons, fewer skills overall and no more secondary profession which = far easier balancing for the devs, and much lower learning curve for the average RPG / MMO player. The learning curve in GW1 was incredibly high, particularly when the game first released and most of the community simply tried to play it like other MMOs / RPGs (I wanna make a paladin, a warrior that also helps the party. Ok, lets see .... Healing Signet for self heal, Frenzy and Power Attack to kill things faster, Mending to become invulnerable and tank, Healing Hands for more tankage, healing breeze to cast on my allies to heal them, and Restore Life to resurrect dead people ....).
And thus was born the legendary Wammo, the single most useless player build ever invented in Guild Wars.