That's like... not true. Like, not even SLIGHTLY true. Dr. Mario is fucking easy, shield-grab down-b, reflector characters reflect pills, short crawlers crouch pills, everyone else shield pills. How did you even come to that conclusion? That fucking baffles me. Could I have the context? Because I am incredibly curious what makes you think that.
Have you ever made a game?
Can I just say that anyone who likes Dr. Mario because "he's essentially Melee Mario" can bite me? First of all, I hate the idea of Mario being a shotoclone in Smash Bros. And second and the whole point of this comment: He's fucking cheap. It's like he can counter anything you throw at him w/o any repercussions. I swear he's the only that needs to be tourney banned.
Dr. Mario can't go deep at all for kills; counter-pick a character with good recovery and you're fine. I would recommend any of the Dudes (and chicks)(and angels) With Swords. Once again, shield Tornado; if he stays on the ground, shield-grab; if he's above you, up-smash or up-b OOS. Tornado has a shit-ton of ending lag.
Who are you playing as? Because it sounds to me like you're just over-reacting to a bad match-up.
Welcome to Smash. I think Meta Knight got his rep because of this kind of early flipouts and ban-happiness.
Your suppose to find the crystal's weak spot (shown by a X shaped crack) by generally smashing the smaller crystals first.