Lol, Funny thing is you don't see only robes running around do you? I see tons of people using leather cloth and plate, Plate of course is more tank based and solider armor is just in a shit place right now, But I do feel leather has some very good options and I don't feel cloth is the best, It may seem like you get better skills on robes plus the more dmg/magic dmg, But leather can do very well with its own skills also, The as jacket gives you a nice INVs with bonus to dmg when attacking right after coming out of INVs, This invs gives you a lot of options to use this skill in different cases, Also you have the hellion jacket which gives you nice life steal and healing to yourself while also making more HP with lower HP and more enemies attacking you the more you steal, Next we have stalker jacket which gives a nice AOE, Next we have the merc jacket with a good healing ability which depends on the dmg you can put out, So with builds that use bleeds or poisen or really any DOT this armor can heal you for a lot and with the right build can be very good, then we have spector jacket, This jacket is very good with the right build and can put out insane dmg if used correct, There are tons of options in this game and really it all comes down to the right build with the right combo of skills. Cloth is good but I don't think its the BEST over everything else at the end of the day. If it was the BEST and super OP everyone would be running around in cloth and that just doesn't happen. zvz is the closest to everyone using cloth and thats just 1 thing you can do ingame. Also want to add that the only reason cloth is used in zvz is because most fights are about the right moment to go in and bomb the other zerg with using cloth this makes theses bombs much more effective, Though while mostly everyone is using cloth in zvz this is why most zvz fights end very fast, That is because only tanks can take tons and tons of dmg, So if you get the right clump and everyone follows up people just get deleted, Because well they are glass cannons, So again its a trade off.The problem is even worse, as now there are many 5-8 sec skills and combos that can be counter-played only with these robes. The devs changed the timings so the players have not a choice, they must play with the robes, which is ridiculous.
Seems you really do not understand the advantage of the robes. It is the combination of highest attack bonus and defensive skills. The leather gear has lower attack bonus, so the defensive skills are not so overpowered in combination. The plate armors are crap, even the soldier one, which has attack bonus, because they do not have so high defense in comparison to the attack bonuses of the robes. Right now with a cleric robe, healing potions and specter you can take much more damage and meanwhile to do much more damage than with any leather or plate armor.