How weird, you've played exactly the same characters in the same way I have.
I wouldn't call it broken though. Once weapon switching kicks in you're pretty much good to go and having the range + melee combo is definitely the best. A lot of the 2 discipline's skills complement each other, especially as a thief. Pulling off a weapon switch combo is pretty satisfying.
One thing I notice a lot of melees doing is not watching. They stand toe to toe with everything. Some strafe around things, which works for some enemies. Hardly anyone watches for the animations, and evades, which are critical now, more so for melee.
I watch but built in evade runs out too quick and you are not left with many, if any evasion skills.
ANY stealth ability will reset the fight and the mob runs off and the cooldown on Steal is way too slow for it to be a reliable boon/offensive control generator.
The only decent weapon so far for survivability has been a bow which has a baked in retreat/evasion skill, but you have to pool Initiative to use it reliably.
With dual daggers I could control groups somewhat with dagger throw to slow, run in, do a single AoE (Fan) attack and retreat for another dagger throw. Rinse repeat. Stealth if it looks like they get too close and try get back in soon enough after to keep them in combat and not regen health.
On my mesmer every single boss type fight has been anti-melee. One boss in the 15-25 zone does a ground stomp. EVEN at my max mesmer range I had to use a jump back evasion skill or even I, at range, would be 1 hit downed.
How on earth does any melee character expect to be even CLOSE to melee capable range? It's somewhat disappointing melee classes rely so very heavily on ranged options and are not given the tools to at least skilfully stay in melee range. You still get whacked in stealth and pulling off a weapon switch to ranged to use an evasion skill after a boss animation starting + reaction time + ping + evasion landing is just not going to happen.
I quite like the look of thief on paper but not if I cannot be melee with it.
All in all anything melee reminds me of playing WoW and trying to kill a single mob double my level with 1% chance of hitting it and if it even got close to me I was dead. I do not feel effective at all, I feel weak, vulnerable and like I am a total third leg in any kind of group encounter.