Why do so many traders prefers MT4 to Others?

The question of the title is likely funny to me because we need MT4 to read, do analysis and trade easily. This is the latest and easiest way tool to trade.

Pay attention to the detail explanation below taken from Hanover in forexfactory forum.

• FREE charting
• FREE live data feed
• FREE historical data
  FREE programming language and test facilities
• FREE demo trading for an unlimited time
• 'No strings attached' trading -- there are no volume quotas to meet, no matter which br0ker you open an account with

- MT4 has the largest number of third party written EAs and indicators available. EAs and scripts allow a potentially infinite number of strategies to be automated, and artificial order type combos (straddles, OCO, hedges, scaling in/out, etc) to be created.
(You may be a manual trader, but what about those thousands of newbies who dream about the possibility of EAs providing passive, effortless income.

- Flexible, comprehensive, user-friendly programming language (the screenshots below were created using MT4 indicators). If you can't find a third party EA or indicator, it's easy to develop one (and if you're not a programmer yourself, forums like FF have instituted a culture where it's easy to find a coder who'll create anything you want, for FREE)

- More than 300 different br0kers to choose from. And if you don't like your current br0ker, you can easily migrate all of your EAs and indicators, and without the nuisance of learning to navigate a different platform. Also, more br0kers = increased competition and incentive to provide better terms and conditions for potential customers (traders).

- In 2014, there were more than 14 million MT4 users worldwide. Hence MT4 is well enough established for its culture to have become deeply ingrained in the 'amateur' trading world. And folk -- especially those who are less computer literate, and want to focus on trading rather than IT complexities -- tend to stick with "the devil they know".

Personally, MT4's biggest drawback is the relatively high transaction costs (spread, slippage, etc) charged by their br0kers, when compared to (for example) Interactive Brokers. But that must be weighed up against the savings I mentioned. And of course it's possible to use MT4 for analysis while running an account with an 'institutional strength' br0ker.

I haven't used Thinkorswim -- but ask yourself, does it tick all of the same boxes?
If the answer is "no", then you have your answer as to why so many folk (for better or worse!) use MT4.

And I personally choose MT4 software to do online trading.