Mining alt coins is better than to directly mine bitcoin. And you will able to convert it to bitcoins directly and you don't have to buy bitcoins. But still we need to consider those people that are not able to trade.
I think mining bitcoin is not worth anymore since the cost of electricity are bigger than profit as my friend experience this.
So I'm usually spend 10% of my salary to purchase bitcoin because I trust bitcoin will gain it's value
Exactly mining is no more profitable nowadays, its better to to buy and hold for the future or invest some part of it in trading which will grow your coins over a period of time.