That's because...
/castsequence Lightning Bolt, Lightning Bolt, Lightning Bolt
...will cast Lightning Bolt once every time you click it. Once three Lightning Bolts have been cast, it will reset the macro. Since you're only using Lightning Bolt in that macro, you'll only see Lightning Bolts being cast. Effectively it's no different from...
/cast Lightning Bolt
...which is just like using no macro in the first place. If you wrote it...
/castsequence Flame Shock, Lightning Bolt, Chain Lightning
...you'd notice that the first time you click it, it will cast Flame Shock, the second time you click it, it will cast Lightning Bolt and the third time Chain Lightning. After the last spell it will reset back to Flame Shock and so on.
You cannot make macros that will automate your playing, though. In other words, you can't make a macro that will cast three Lightning Bolts for you. You have to click each time you want it to cast a new spell, or one more of the same type. This is to prevent people from making macros that would play the game for them.
Edited, Feb 21st 2010 2:34am by Mazra
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